Question

How look diagrams of y=sin²x+cos²x ; y=sin²x-cos²x ; y=sinx*cosx ?

Answer 1

ok
sin^2x+cos^2x=1
right?
so if u plot this
just a constant function with unity value

Answer 2

ok?

Answer 3

ok

Answer 4

now for the second function --
do know this identity
\[\cos2x=\cos^2x-\sin^2x\]

Answer 5

then
\[-\cos2x=\sin^2x-\cos^2x\]
right?

Answer 6

yep

Answer 7

so we have to plot (-cos2x) right?

Answer 8

yes

Answer 9

now cos(2x) looks like this