Question

sin power 4 x minus cos power 4 x

Answer 1

sin^4-cos^4
using (a^2-b^2) formula
(sin^2+cos^2) (sin^2-cos^2)
1( sin^2-cos^2)


hope it helped u....

Answer 2

${ \sin }^{4} x- { \cos}^{4} x \\ \\ = ( { \sin }^{2} x+ { \cos}^{2} x) \times ( { \sin}^{2}x - { \cos }^{2} x) \\ \\ = 1 \times ( { \sin}^{2}x - { \cos }^{2} x) \\ \\ = \boxed{{ \sin}^{2}x - { \cos }^{2} x}$
$= (1 - { \cos }^{2} x) - { \cos }^{2} x \\ \\ = 1 - 2 { \cos}^{2} x \\ \\ = \boxed{ - \cos(2x) }$