Question

Let f be defined by f(x)=−x^2−3x+5.
f'(x)=-2x-3
An equation for the tangent line to y=f(x) at x=−1 is y=?

Answer 1

i guess y comes out to be y=6-x

Answer 2

you know the answer eq?

Answer 3

how did u come out with y=6-x?

Answer 4

at x=-1 y ll be y=7 right? like y= -(-1)^2-3(-1)+5=7

Answer 5

and f'(x)=-1

Answer 6

putting values in tangent eq (y-7)=(-1)(x-(-1))

Answer 7

y=6-x.isn't it?

Answer 8

that's right, but how did u know that t m=-1?

Answer 9

o thats easy look slope has a point on function and they gave us a point x=-1 ok? put x=-1 in the eq f'(x) =-2x-3 when we put x=-1...f'(x)= -2(-1)-3=2-3=-1

Answer 10

ooh i get it thank u

Answer 11

welcome:)