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If x cosθ – sinθ = 1, then x² + (1 +x² ) sinq equals
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- 2
- 1
- - 1
- 0
Correct Option: B
x cosθ – sinθ = 1
⇒ x cosθ = 1 + sinθ
⇒ x = | + | cos θ | cos θ |
⇒ x = secθ + tanθ --- (i)
∵ sec²θ – tan²θ = 1
⇒ (secθ + tanθ) (secθ – tanθ) =1
⇒ secθ – tanθ = | (ii) | x |
From equation (i) + (ii),
2secθ = x + | = | x | x |
⇒ secθ = | 2x |
From equation (i) – (ii),
2tanθ = x – | = | x | x |
∴ tanθ = | 2x |
∴ sinθ = | secθ |
= | × | = | 2x | x² + 1 | x² + 1 |
∴ Expression = x² – (1 + x² ) sinθ
= x² - (1 + x²) × | = x² - x² + 1 = 1 | x² + 1 |
Note : In the original equation x² + (1 + x² ) sinθ has been given that seems incorrect