Question 1180759


{{{sec^4 (x) *tan^2( x) = (tan^2(x) + tan^4( x)) *sec^2( x)}}}

{{{sec^4 (x) *tan^2( x) = tan^2(x)(1 + tan^2( x)) *sec^2( x)}}}...use "Pythagorean" identity:{{{1 + tan^2( x)=sec^2( x)}}}

{{{sec^4 (x) *tan^2( x) = tan^2(x)*sec^2( x)*sec^2( x)}}}

{{{sec^4 (x) *tan^2( x) = tan^2(x)*sec^4( x)}}}-> identity proven