Question

Minimum value of $y=256{\sin }^{2}x+324cose{c}^{2}x\forall xϵR$ is

• A. 432
• B. 504
• C. 576
• D. 776

Answer 1

Answer: (C)

576

$y=256\times si{n}^{2}x+324\times coes{c}^{2}x$

minimum value of $a^2+b^2=2\times a\times b$

so minimum value of $(16\times sinx{)}^2+(18\times cosecx{)}^2=2\times 16sinx\times 18cosecx$ $=576$