Question 61

If α + β = 90° and α:β = 2:1, then the ratio of cosα to cosβ is

Solution

Given : α + β = 90° and α:β = 2:1

Let $$\alpha=2x$$ and $$\beta=x$$

=> $$2x+x=90^\circ$$

=> $$x=\frac{90}{2}=30^\circ$$

=> $$\alpha = 60^\circ$$ and $$\beta=30^\circ$$

$$\therefore$$ $$\frac{cos\alpha}{cos\beta}=\frac{cos(60^\circ)}{cos(30^\circ)}$$

= $$\frac{\frac{1}{2}}{\frac{\sqrt{3}}{2}}=\frac{1}{\sqrt{3}}$$

=> Ans - (A)

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: