Find the value of the following:3 sin 60° – 4 sin360°

Let θ = 60°then,3 sin 60° – 4 sin360°= 3sinθ - 4sin3θWe know thatSin3θ = 3sinθ - 4sin3θ⇒ 3 sin 60° – 4 sin360°= sin(3 × 60° )= sin 180°= 0

Q4 of 44 Page 79

Find the value of the following:
3 sin 60° – 4 sin³60°

Let θ = 60°

then,

3 sin 60° – 4 sin³60°

= 3sinθ - 4sin³θ

We know that

Sin3θ = 3sinθ - 4sin³θ

⇒ 3 sin 60° – 4 sin³60°

= sin(3 × 60° )

= sin 180°

= 0

Find the value of the following:

cos 45° cos 60° – sin 45° sin 60°

Find the value of the following:

sin²30° + 2 cos²45° + 3 tan²60°

Find the value of the following:

4cot²45° – sec²60° + sin²60° + cos²90°

Questions · 44

6. Trigonometric Ratios

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