Question

sin³+cos³=(sin+cos)(1-sin.cos)

Answer 1

a^3+b^3=(a+b)(a^2+b^2-ab)

use this formula in lhs we get

(sina+cosa)(sin^2a+cos^2a-sinacosa)

we know
sin^2+cos^2=1
put in above equation we get
(sina+cosa)(1-sinacosb)

Answer 2

Step-by-step explanation:

we know

sin^2+cos^2=1

put in above equation we get

(sina+cosa)(1-sinacosb)