Question

sin^72°-cos^30°=root5-1/8​

Answer 1

Answer:

$\sin72 {}^{o} - \cos30 {}^{o} = \sqrt{5} - \frac{1}{8} \\ \sin72 {}^{o} = \cos30 {}^{o} + \sqrt{5} - \frac{1}{8} \\ \sin72 {}^{o} = \frac{ \sqrt{3} }{2} + \sqrt{5} - \frac{1}{8} \\ \sin72 {}^{o} = \frac{4 \sqrt{3} + 8 \sqrt{5} - 1}{8} \\ \sin72 {}^{o} = \frac{6.9282 + 17.8885 - 1}{8} \\ \sin72 {}^{o} = \frac{23.8167}{8} = 2.977$