Find the point on the parabola y=x^2 at which the tangent line is parallel to the line 2x+y=0

a.) (1,1) b.) (0,0) c.) (-1,1) d. (2,4) e.) (-2,4)

Question

Find the point on the parabola y=x^2 at which the tangent line is parallel to the line 2x+y=0

a.) (1,1)   b.) (0,0)  c.) (-1,1)  d. (2,4)  e.) (-2,4)

phi · Answer

y=x^2

do you know how to take the derivative?  that will give an equation that tells you the slope of the tangent line at any point x

phi · Answer

also,
you need the slope of 
2x+y=0

in y = mx +b format  you have
y = -2x

this tells you m = -2   and b=0
m is the slope

anonymous · Answer

derivative is 2x right?

phi · Answer

yes.  
so you want

2x = -2

solve for x

then use that value to find y =  x^2

anonymous · Answer

so if slope of 2x+y=0 is -2; and using the derivative of y=x^2 (which is 2x); then my equation should be 2x = -2 (to find the x?) which results in -1 for the point x. substituting that with the original function y=x^2 then the results for y of the point is 1 so the answers is (-1,1) aka letter c?

anonymous · Answer

oh! thanks i didn't see the last comment. Thank you!