Question

can someone show me how the limit of (cosx-1)/(sin^2(x) is equal to -1/2 as x approach to 0 WITHOUT La Hopital please?

Answer 1

sin^2x= 1-cos^2x

Answer 2

then factor out a negative one out of the top and you get -(1-cosx)/((1-cosx)*(1+cosx)) cancel out the tops and bottom part that is the same and you plug in then you win!

Answer 3

I thought sin^2x= 1-cos(2x), not 1-cos^2(x)

Answer 4

sorry..Pythagorean identity. i see now