Question

find the value of the following with the help of radian measure (2 marks)
$\sin^{2} ( \frac{\pi}{6} ) + \cos {}^{2} ( \frac{\pi}{3} ) - \tan {}^{2} ( \frac{\pi}{4} ) + \cos {}^{2} ( \frac{\pi}{4} )$
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Answer 1

Answer:

Now,

Let a=sin26π+cos23π−tan24π

We know that,  sin6π=21 and cos6π=21,tan4π=1

a=41+41−1

a=21−1

a=−21.

Hence, proved