Section A - Data Interpretation and Quantitative Ability

14 What is the maximum possible value of (21 sin X + 72 cos X)?

A. 21 B. 57 C. 63 D. 75 E. None of the above

Explanation:

The maximum value of E = a cosx + b sinx is Proof:

E =

(

Let sinq = \ cosq =

E = (sinq cosx + cosq sinx)

= sin(q + x)

\ The maximum/minimum values of E are

±

In the given question a = 72 = 3(24)

b = 21 = 3(7)

\ = 3(25) = 75 Choice (D)