Question

(cos 0 + sin 30 + sin 45) (sin 90 + cos 60 - cos 45) = ? (a) 5/6 (b) 5/8 (c) 3/5 (d) 7/4​

Answer 1

Step-by-step explanation:

(cos0+ sin 30+ sin 45)(sin 90+cos60-cos45)

(1+1/2+1/√2)(1+1/2-1/√2)

(a+b)(a-b)=a square - b square

(1+1/2)^2-(1/√2)^2

(3/2)^2 -1/2

9/4 -1/2

9-2/4

7/4