Question
Simplify the following trigonometric expression:
/>12 cos 68o cosec 22o - 3 cot 72o cot 18oSolution
12cos 68o cosec 22o - 3cot 72o cot 18o
= 12cos 68o cosec (90o - 68o) - 3cot 72o cot (90o - 72o)
Using, cosec (90o - A) = sec A and cot (90o - A) = tan A
= 12 cos 68o sec 68o - 3 cot 72o tan 72o
Since, sec A is reciprocal of cos A and cot A is reciprocal of tan A.
= 12 - 3 = 9
The most reactive among the halogens is-
Manganite is an ore/mineral of
The major component of honey is-
Which of the following is a physical change?
Petroleum is a mixture of-
The fuel that is used in modern submarines is -
The important ore of aluminium is-
The element used for making solar cells is
Which one amongst the following is not a Green House gas?
The noble gas used in radiotherapy is