Question

Tolong dikasih oembuktiannya yaa makasih..

Answer 1

Ingat pada persamaan kuadrat ada rumus
(x1)^3 + (x2)^3 = (x1 + x2)^3 - 3.x1.x2 (x1 + x2)

sin^3 A + cos^3 A
-------------------------
1 - sin A cos A

(sin A + cos A)^3 - 3 sin A cos A (sin A + cos A)
-------------------------------------------------------------------
1 - sin A cos A

(sin A + cos A) [(sin A + cos A)^2 - 3 sin A cos A]
--------------------------------------------------------------------
1 - sin A cos A

(sin A + cos A)(sin^2 A + 2 sin A cos A + cos^2 A - 3 sin A cos A)
--------------------------------------------------------------------------------------------
1 - sin A cos A

(sin A + cos A)(sin^2 A + cos^2 A + 2 sin A cos A - 3 sin A cos A)
--------------------------------------------------------------------------------------------
1 - sin A cos A

(sin A + cos A) (1 - sin A cos A)
--------------------------------------------
1 - sin A cos A

Sin A + cos A ..... (Terbukti)