Question 24

∆XYZ is right angled at Y. If m∠X = 30°, then find the value of (cosZ + 1/3).

Solution

Sum of angles of $$\triangle$$ XYZ = $$\angle X+\angle Y+\angle Z=180^\circ$$

=> $$30^\circ+90^\circ+\angle Z=180^\circ$$

=> $$\angle Z=180^\circ-120^\circ=60^\circ$$

To find : $$(\cos Z +\frac{1}{3})$$

= $$cos(60^\circ)+\frac{1}{3}$$

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

= $$\frac{5}{6}$$

=> Ans - (D)

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: