If $\cos^2\theta - \sin^2\theta = \dfrac{1}{2}$, then $\cos^4\theta - \sin^4\theta = ?$

C-09-Q198mediumsingle_mcq

If $\cos^2\theta - \sin^2\theta = \dfrac{1}{2}$ , then

−

sin2θ=

21

\cos^4\theta - \sin^4\theta = ?

a $1$
b $\dfrac{1}{2}$
c $\dfrac{2}{3}$
d $\dfrac{1}{3}$

ব্যাখ্যা

Factoring, $\cos^4\theta-\sin^4\theta=(\cos^2\theta-\sin^2\theta)(\cos^2\theta+\sin^2\theta)$ . Since $\cos^2\theta+\sin^2\theta=1$ , this equals $\cos^2\theta-\sin^2\theta=\tfrac12$ .

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Trigonometric Ratio — সব প্রশ্ন দেখুন (217টি) →

1

If cos⁡2θ−sin⁡2θ=12\cos^2\theta - \sin^2\theta = \dfrac{1}{2}cos2θ, then

If cos⁡2θ−sin⁡2θ=12\cos^2\theta - \sin^2\theta = \dfrac{1}{2}cos2θ, then

ব্যাখ্যা

এই অধ্যায়ের আরও প্রশ্ন

If $\cos^2\theta - \sin^2\theta = \dfrac{1}{2}$ , then

If $\cos^2\theta - \sin^2\theta = \dfrac{1}{2}$ , then