Math 142 - Exam 3 Concepts and Review (3.4-4.4)
power antiderivative rule ∫xⁿdx=
(1/n+1)xⁿ⁺¹ +C
what is the formula to determine ∆x (∆t)?
(b-a)/n ; n : number of subintervals (rectangles)
Steps to first derivative test
1. determine domain of f 2. find partition numbers 3. determine which partition numbers are in domain --- these are the critical values 4. create a sign chart of f' in domain of f
3 steps of closed interval method
1. determine domain of f and check that the function is continuous on the closed interval. if f is not continuous on the interval we cannot use this method 2. find the critical values of f. recall that these are the x values where f'(x) =0 or f'(x) DNE, and they're in the domain of f 3. evaluate f at the critical values in the interval and the endpoints of the interval, and determine the largest (absolute max) and smallest (abs min) values.
steps of finding a specific antiderivative
1. find the most general antiderivative 2. solve for the constant of integration C using the point given 3. substitute this value of C back into general antiderivative
what is the area of a semicircle
A=½πr²
what is the equation for revenue
Revenue = Price x Quantity
surface area of a box w open lid
S= x^2 +4xy
local or absolute extrema?: function can only have at most one of this extrema (y value)
absolute extrema
local or absolute extrema?: occur inside the function at max/min or at an end point
absolute extrema
what is constant C called
constant of integration
this equation is what you know
constraint equation
function has absolute minimum if its values go from
decrease to increase
du and dx are called
differentials
f(c) is an absolute minimum of f if...
f(c)≤ f(x) for all x in the domain of f
f(c) is an absolute maximum of f if ....
f(c)≥f(x) for all x in the domain of f
t or f : local and absolute extrema can occur at a hole
false
t or f: when problem says to find the absolute extrema of f it means the answer will be the x value of the point
false; the answer will be the y value of the max/min
t or f: the x*i value is the width of the rectangle
false; the x*i value is the height of the rectangle and the ∆x value is the width
t or f: in order to use case 2 there can be more than one exponential chain rule in the integrand
false; there can only be one b^g(x)/e^g(x)
t or f: when using u substitution with definite integrals the values of integrals given are okay to use
false; they are in terms of x so you would have to change them into terms of u by plugging the x values into the equation that equals u
fourth step of optimization process:
find the critical values of the objective function then move on to either use CIM (buis) or FDT/SDT (geometry)
third step of optimization process
find the interval on which the objective function must be optimized. to do this consider the context of the problem and restrict the variables to determine a realistic domain for the objective function
first step of solving optimization problem: geometry:
identify the quantity you want to max/min and the quantity that you know; draw a picture with labels and introduce variables; determine the relationships between the variables to create the objective function and possibly a constraint equation
first step of solving optimization problem : buisiness
identify the quantity you want to max/min and the quantity that you know; introduce variables; determine the relationships between the variables to create the objective function and possibly a constraint equation
extreme value theorem
if a function is continuous on a closed interval [a,b], then it must have both an absolute maximum and absolute minimum on the interval
first part of fundamental theorem of calculus
if f is continuous on an interval [a,b] and the function F is defined by F(x)= ∫a^x f(t) dt - where a≤x≤b then F'(x) = f(x) on the interval [a,b]
part two of the fundamental theorem of calculus
if f is continuous on the interval [a,b] and F is any antiderivative of f then ∫a^b f (x) dx = F(b) = F(a)
function has absolute maximum if its values go from
increase to decrease
what does dx indicate
integration w respect to x
f(c) is an absolute extremum of f if f(c)...
is an absolute max or absolute min
when is the area of regions between the function and the x axis considered to be a negative value
it is a negative value where the function is negative
constant antiderivative rule ∫kdx =
kx+C
local or absolute extrema? : occur inside the function
local extrema
local or absolute extrema?: multiple of this extrema can occur in a function (y value)
local extrema
this function is what you want
objective function
what is the function we are maximizing or minimizing called
objective function
when can Reimann sums be used to estimate the net area ?
when the function values are negative
"that" means to find the
x value
"where" means
x value
the width of the subintervals (rectangle) is referred to as
∆t (in a velocity time graph) but ∆x in general
integral sign
∫
case 3 of possible substitution cases
∫(1/g(x))×g'(x) dx
case 2 of possible substitution cases
∫b^(g(x))×g'(x) dx where b is any pos real number
special case of exponential antiderivative rule
∫e^xdx = e^x +C
case 1 of possible substitution cases
∫g(x)ⁿ×g'(x) dx where n is any real number w n≠1
special case of the power antiderivative rule
∫x⁻¹dx = ∫1/x dx = ln|x| +C
Properties of Definite Integrals
1. if the limits of integration are the same then there is no area ∫ⁿₙf(x) dx = 0 2. reversing the order of the limits of integration will change the sign of the definite integral ∫f(x) from [a,b] = −∫f(x) of [b,a] 3. the definite integral of a sum (or difference) is the sum (or difference) of the definite integrals 4. if we multiply a function by a constant and then find the definite integral it is equivalent to finding the definite integral of the function and then multiplying by the constant 5. a region can be divided into two separate regions and the area will remain the same whether we calculate it all as one region or as two separate regions ∫a^b = ∫a^c + ∫c^b
steps to perform substitution
1. let u = g(x) 2. write du = g'(x) dx 3. Rewrite the integral in terms of u and du 4. integrate 5. substitute back for u
exponential antiderivative rule ∫b^x dx=
1/ln(b)×b^x +C
the summation of all of the areas of "rectangles" is called a
reimann sum
second step of optimization process
state objective function in terms of one variable. if there is more than one variable then solve the constraint equation for one variable and substitute in the objective function
the process of reversing the chain rule to find an antiderivative
substitution or u-substitution
on a graph displaying the relationship between time and velocity how do you find distance?
the area under the line of this graph would equal to the distance
integrand
the function f that follows the integral sign
what is optimization
the process of finding an absolute max or min
integration
the process of finding the most general antiderivative of a function
what is a sample point
the x*i value we chose in each interval to determine the height of a particular rectangle
"is" means to find the
the y value
why do we use the closed interval method?
to compare the values of the function at the critical values in the interval and the endpoints of the interval
when do you use the closed interval method?
to find the absolute extrema of a function on a closed interval on which the function is continuous;
t or f : a function will have infinitely many antiderivatives
true
t or f : for geometric optimization problems FDT or SDT can be used in the fourth step
true
t or f : when you take the limit of the Reimann sum the answer will be exact and not an estimate
true
t or f: Reimann sum is used to find an ESTIMATE of the area between the x axis and curve/line of a function
true
t or f: every business optimization problem should have a closed interval so CIM will be used
true
t or f: if you increase the number of rectangles used in a Riemann sum the estimation will approach the exact answer
true
t or f: in the third step of optimization (buis problem) p is always greater than or equal to 0
true
t or f: it can be assumed that C= 0 because part 2 of the FTC says we can use any antiderivative to evaluate a definite integral
true
t or f: the area under a velocity curve is the change in position of an object during that intervals time
true
t or f: where f' is positive f increases and where f' is negative f decreases
true
t or f: where f'' is negative f' decreases and f is concave down and where f'' is positive f' increases and f is concave up
true
t or f: you can have local extrema even if f is not continuous
true
true or false: a function can only have one absolute max/min y value but can occur at multiple x value
true
t or f: local extrema cannot occur at an endpoint
true; function would need to occur on either side of the point even if a random point closed circle