Help please!
Use the Mean Value Theorem to
1) Find the point c on (a,b) at which the tangent line of the following function is parallel to the secant line
2) Write an equation for the tangent line
f(x)=-x^2+6x [1,4]
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
myininaya (myininaya):
so you know you need this:
\[f'(c)=\frac{f(b)-f(a)}{b-a}\]
myininaya (myininaya):
f'(c) tells you to find the derivative of f
and then evaluate f' at c
--
b tells you to plug in 4
a tells you to plug in 1
OpenStudy (anthonyn2121):
Okay I got f'(x) -2x+6 and [f(4)-f(1)]/3 = 1. And x=7/2
myininaya (myininaya):
so -2x+6=1
-2x=1-6 right
myininaya (myininaya):
1-6 isn't -7 but -5 right?
Still Need Help?
Join the QuestionCove community and study together with friends!
Sign Up
myininaya (myininaya):
i think you know that
-2x=-5
so x=5/2 not 7/2
myininaya (myininaya):
so you are asked to find the tangent line to the point (5/2,f(5/2)) to the curve f=-x^2+6x
myininaya (myininaya):
so you do this:
y-f(5/2)=f'(5/2)*(x-5/2)
you need to find f(5/2) and also f'(5/2)
OpenStudy (anthonyn2121):
I got f'(5/2)=1 and f(5/2)=35/4. So my final answer is y-(35/4)=x-(5/2)
myininaya (myininaya):
looks great
Still Need Help?
Join the QuestionCove community and study together with friends!