If sin3A = x, then value of x is
Expression : sin3A = X
= $$sin(2A+A)$$
= $$sin(2A)cosA+cos(2A)sinA$$
= $$(2sinAcosA)cosA + (1-2sin^2A)sinA$$
= $$2sinA(cos^2A) + sinA - 2sin^3A$$
=Â $$2sina(1-sin^2A)+sinA-2sin^3A$$
= $$2sinA-2sin^3A+sinA-2sin^3A$$
= $$3sinA-4sin^3A$$
=> Ans - (D)
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