If sinA1, + sinA2 + sinA3 = 3 then cosA1+ cosA2 + cosA3 =(A) 3(B) 2(C)

1.	If sinA1, + sinA2 + sinA3 = 3 then cosA1+ cosA2 + cosA3 =(A) 3(B) 2(C) 1(D) 0
Answer» Answer:(D) 0 Step-by-step explanation: Sina1 + SINA2 + SINA3 = 3 we know , sine maximum value= 1 so, above expression is CORRECT only when , sina1 = sina2 = sina3 = 1 e.g a1 = a2 = a3 = 90° but we know , cos90° = 0 so, cosa1 = cosa2 = cosa3 = 0 hence, cos a1+cos a2+cos a3=0

If sinA1, + sinA2 + sinA3 = 3 then cosA1+ cosA2 + cosA3 =(A) 3(B) 2(C) 1(D) 0

Answer»

Answer:(D) 0

Step-by-step explanation:

Sina1 + SINA2 + SINA3 = 3

we know ,

sine maximum value= 1

so, above expression is CORRECT only when , sina1 = sina2 = sina3 = 1

e.g a1 = a2 = a3 = 90°

but we know ,

cos90° = 0

so, cosa1 = cosa2 = cosa3 = 0

hence,

cos a1+cos a2+cos a3=0