Question
What is the value of
cos75°?Solution
cos75o = cos(45 + 30)o Since, cos(A + B) = cosAcosB – sinAsinB So, cos 75o = cos45ocos30o – sin45osin30o = {(1/√2) × (√3/2) – (1/√2) × (1/2)} = (√3/2√2) – (1/2√2) = (1/2√2) × (√3 – 1) On multiplying both numerator and denominator by √2, we have; = (√2/4) × (√3 – 1)
A monkey climbs a tower of height 60 m. It climbs 5m above in 1st minute and 4m below in 2nd minute. In how many minutes monkey wi...
Suppose '68472m' is divisible by 6 but not divisible by 5. Find the value of (m × 3 - 2).
Sum of squares of three consecutive numbers is 974. Find the sum of first and third number.
99² +? ² = 18826
Divide 45 into 4 parts such that if the first is increased by 2, the second is decrease by 2, the third is multiplied by 2 and the fourth divided by 2, ...
The sum of three consecutive odd natural numbers each divisible by 3 is 81. Which number is the largest number among the three numbers?
- The sum of two numbers is 90 whereas the sum of their reciprocals is (30/11). Find the square of the product of the two numbers.
Range of the given data 23,19,16,17,21,9,18,6.
- When a number is divided by 31, the remainder is 28. Find the remainder when twice the number is divided by 31.
- The number of marbles with Amit and Rahul is 14 more than with Kabir. Rahul and Kabir together have 4 more marbles than Amit. If Amit and Kabir together ha...
Relevant for Exams:
