If sinθ = $\frac{8}{17}$, and θ lies in the 2nd quadrant, find cosθ.
$\frac{-15}{17}$
Using \(\sin^2\theta + \cos^2\theta = 1\), \(\cos\theta = \pm\sqrt{1 - (8/17)^2} = \pm 15/17\). Since θ lies in the second quadrant, cosine is negative, so \(\cos\theta = -15/17\).
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Important Questions from Trigonometric Ratios and Identities
If cosec θ = 13/12, then sin θ + cos θ - tan θ is equal to:
What is the value of \(\frac{3 \sin 58^{\circ}}{\cos 32^{\circ}}+\frac{3 \sin 42^{\circ}}{\cos 48^{\circ}}\) ?
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If α + β = 90° and α = 2β, then the value of 3 cos 2 α - 2 sin 2 β is equal to:
If \(\sqrt{3}\) tan θ = 3 sin θ, then what is the value of sin 2θ − cos 2θ ?
