Question

find the value of 3sin 30'-4sin³60'​

Answer 1

Answer:

Using trigonometric tables we get:-

$sin \: 30 = \frac{1}{2}$

$sin \: \: 60 = \frac{ \sqrt{3} }{2}$

Solution:-

$3 \: sin 30-4 {sin}^{3} 60$

$= 3 \times \frac{1}{2} -4 \times ( { \frac{ \sqrt{3} }{2} })^{3}$

$= \frac{3}{2 } - 4 \times \frac{3 \sqrt{3} }{8}$

$= \frac{3}{2} - \frac{3 \sqrt{3} }{2}$

$= \frac{3 - 3 \sqrt{3} }{2}$