Q. 21

# Mark the Correct alternative in the following:

The number of values of x in the interval [0. 5 π] satisfying the equation 3 sin^{2} x – 7 sin x + 2 = 0 is

A. 0

B. 5

C. 6

D. 10

Answer :

3sin^{2}x-7sin x+2=0

Solving the equation, we get

=19.47122

x= nπ + (-1)^{n} a

For

n=0, x=a

n=1, x = π – a

n=2, x = 2π + a

n=3, x = 3π – a

n=4, x = 4π + a

n=5, x = 5π + a

So, there are 6 values less then 5π.

Option C.

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