## britbrat4290 Group Title Show that the equation is not an identity by finding a value of x for which both sides are defined but not equal. cos x - cos x sinx = cos3 x pi/4 or pi/2 ?????? one year ago one year ago

1. Psymon

cos(3x) or cos^3(x)?

2. amistre64

cospi/2 = 0 soo thats not it

3. britbrat4290

it would be 0... thank u

4. amistre64

now that depends on of its $$\cos^3x$$ or $$\cos 3x$$