Question

solve this step by step​

Answer 1

Answer:

4

Step-by-step explanation:

$sinA + sin^2A + sin^3A = 1sinA + sin^3A = 1 - sin^2A = cos^2AsinA(1+sin^2A) = cos^2AsinA(2 -cos^2A) = cos^2A$

Then square both sides:

$sin^2A(4-4cos^2A +cos^4A) = cos^4A(1-cos^2A)(4-4cos^2A +cos^4A) = cos^4A4-4cos^2A +cos^4A-4cos^2A+4cos^A-cos^6A = cos^4A4 -cos^6A +4cos^4A -8cos^2A = 0$

Finally:

$cos^6A - 4 cos^4A + 8cos^2A = 4$

Hope you understood!