NCERT SOLUTIONS FOR CLASS 11 MATHS CHAPTER 3 / TRIGONOMETRIC FUNCTIONS EX 3.2 /

Find the values of other five trigonometric functions in Exercises 1 to 5.

Question 1. $\cos { x } =\frac { -1 }{ 2 }$ , x lies in third quadrant.

Solution.

Question 2. $\sin { x } =\frac { 3 }{ 5 }$ , x lies in second quadrant.

Solution.

Question 3. $\cot { x= } \frac { 3 }{ 4 }$ , xlies in third quadrant.

Solution.

Question 4. $\sec { x } =\frac { 13 }{ 5 }$ , x lies in fourth quadrant.

Solution.

Question 5. $\tan { x } =-\frac { 5 }{ 12 }$ , x lies in second quadrant.

Solution.

It is given that

tan x = – 5/12

We can write it as

We know that

1 + tan² x = sec² x

We can write it as

1 + (-5/12)² = sec² x

Substituting the values

1 + 25/144 = sec² x

sec² x = 169/144

sec x = ± 13/12

Here x lies in the second quadrant so the value of sec x will be negative

sec x = – 13/12

We can write it as

Find the values of the trigonometric functions in Exercises 6 to 10.

Question 6. sin 765°

Solution.

Question 7. cosec (-1410°)

Solution.

Question 8. $tan\quad \frac { 19\pi }{ 3 }$

Solution.

Question 9. $sin\left( -\frac { 11\pi }{ 3 } \right)$

Solution.

Question 10. $cot\left( -\frac { 15\pi }{ 4 } \right)$

Solution.