Solution:
Given:

To get sin 240 degrees:
240 degrees falls in the third quadrant.
In the third quadrant, only tangent is positive. Hence, sin 240 will be negative.

Using the trigonometric identity;

Hence,

To get cos 240 degrees:
240 degrees falls in the third quadrant.
In the third quadrant, only tangent is positive. Hence, cos 240 will be negative.

Using the trigonometric identity;

Hence,

To get tan 240 degrees:
240 degrees falls in the third quadrant.
In the third quadrant, only tangent is positive. Hence, tan 240 will be positive.

Using the trigonometric identity;

Hence,

To get cosec 240 degrees:

To get sec 240 degrees:

To get cot 240 degrees:
where is the figures to solve.
For these problems you have to use PEMDAS so for problem 15 you would do the parentheses first, (21-3) you get 18 and then exponents, 3^2, you get 9, no multiplication but there is division so take your answers, 18 and 9 and divide them, you get 2, so the answer to 15 is 2.