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SSC CGL 2020 PYQ — Question 60

SSC CGL - 3rd March 2020 Shift 1 • Quantitative Aptitude • Q60

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If x = 4cosA + 5sinA and y = 4sinA - 5cosA, then the value of x2 + y2 is:

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Correct answer: C

Explanation

The correct answer is Option 3 i.e. 41

Understanding Application
Tricks

Here we take A = 90 (you can take any value)

x = 4cosA + 5sinA

So

x = 4cos90 + 5sin90

= 0 + 5(1)

= 5
Now

y = 4sinA - 5cosA

y = 4sin90 - 5cos90

= 4(1) + 0

= 4
Hence

x2 + y2 = 52 + 42

= 25 + 16

= 41