Question
If P . cos θ + Q . sin θ = 8 and P . sin θ - Q . cos
θ = 5, what is the value of (P² + Q²)?Solution
Given, P . cos θ + Q . sin θ = 8 ⇒ P² . cos² θ + Q² . sin² θ + 2PQ . sin θ . cos θ = 64  … (i) Also given, P . sin θ - Q . cos θ = 5 ⇒ P² . sin² θ + Q² . cos² θ - 2PQ . sin θ . cos θ = 25  … (ii) Adding equations (i) and (ii) P² + Q² = 89
More Trigonometry Questions
15.99% of 549.99 ÷ 11.17 = ? ÷ 20.15
74.91% of 639.95 – 599.98% of 45 + 119.987 = ?
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- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exact value.)
- What approximate value will come in place of the question mark (?) in the following question? (Note: You are not expected to calculate the exactvalue.)
(1800.23 ÷ 29.98) + (816.32 ÷ 23.9) + 1634.11 = ?
1449.98 ÷ 50.48 × 10.12 = ? × 2.16
36.05 × 5.02 + 12.052 = ? + 9.09 × 4.04Â
(31.9)3 + (34.021)² - (16.11)3 - (42.98)² = ?
