Question

Please help me to find the slope of the tangent line to the given curve at the given value of x and find the equation of each tangent line :
Y=8-x^2 at x=1

I don't just need a answer, I need to know how to work it....Thanks in advance :)

Answer 1

see differentiate wrt x on both sides

Answer 2

both sides of what?

Answer 3

both sides of ur equation
y = 8 - x^2

Answer 4

ok

Answer 5

do it and show it to me

Answer 6

u there?

Answer 7

sorry computer froze...1 sec

Answer 8

I thought that in order to find the slope of a tangent it would be to write f(x) = 8-x^2
and a=1

Answer 9

wts a?

Answer 10

Slope of a tangent should be ((1+h)^2+8) - ...............disregard.....Thank You!

Answer 11

youre going totally off track now
differentiate both sides

dy/dx = -2x

slope is dy/dx at x=1
hence slope is -2
get it?

Answer 12

the equation of the tangent line should be \[\lim_{h \rightarrow 0} [f \left( x+h \right)-f \left( x \right)]\div h\]which will get you -2x and by placing x=1 you can find the slope at x=1

Answer 13

do u know differentiation?

Answer 14

I apologize but my computer is acting up tonight........

Answer 15

@ kanade, that is the formula I was using, that is why I was so confused with @him1618, I am not that good in calculus/stats so if you tell me terms and stuff I get lost

Answer 16

find a tangent gradient with diferentiate y=8-x^2 to y'=-2x
fill x with the point x=1
and then you will get the gradient, use it to get equation with formula
y-y1=m(x-x1), which m = gradient, (x1,y1) is a point which we want to know about equation