CAT – Trigonometry Questions


Question:
3sinx + 4cosx + r is always greater than or equal to 0. What is the smallest value ‘r’ can to take?
A.  5
B.  -5
C.  4
D.  3
Correct Answer: (A)

 

Explanation:
3sinx + 4cosx -r
-r
= cosA  => sinA =
5(sinx cosA + sinA cosA) -r
5(sin(x + A) -r
5sin (x + A) -r
-1 < sin (angle) <1
5sin (x + A) -5
rmin = 5
Difficulty Level 2

Related posts

  • CAT Counting: Question with digitsMay 23, 2013 CAT Counting: Question with digits This is an interesting question from Counting. Simple framework, but one needs to be very careful with the enumeration. One can get wrong answers in a number of […] Posted in Combinatorics
  • Profit and Loss QuestionAugust 24, 2013 Profit and Loss Question Question: A merchant can buy goods at the rate of Rs. 20 per good. The particular good is part of an overall collection and the value is linked to the number of items that are […] Posted in Uncategorized, Profit and Loss
  • CAT – PercentsAugust 21, 2013 CAT – Percents Question:    P is x% more than Q. Q is (x - 10)% less than R. If P > R, what is the range of values x can take? A.  10% to 28% B.  10% to 25% C.  10% to 37% D.  10% to […] Posted in Percentages
  • CAT – PercentagesJanuary 16, 2013 CAT – Percentages This is an interesting question from Percentages. Simple framework, but finding the answer is not that easy Question A is x% more than B and is x% of sum of A and B. What is […] Posted in Percentages

Leave a Reply

Your email address will not be published. Required fields are marked *