Given :
An equation, 2cos ß sin ß = cos ß .
To Find :
The value for above equation in (0, 2π ] .
Solution :
Now, 2cos ß sin ß = cos ß
2 sin ß = 1
sin ß = 1/2
We know, sin ß = sin (π/6) or sin ß = sin (5π/6) in ( 0, 2π ] .
Therefore,

Hence, this is the required solution.
To answer this question, use permutation since the order of the letter matters. There are 7 letters and only 4 are to be used for the code. This is a permutation of 7 taken 4 (7P4) which is equal to 840. Thus, the sample space is 840.
For the next questions, there are 3 vowels for as the first letter, only 6 letters are available for the second, 5 on the next, and 4 on the last. Multiplying these numbers give 360. To solve for probability, divide this number with the sample space. Thus, the answer is 3/7.
The correct answer is B. So for A, 8m is smaller than 12 m. For B, 20 m is Bigger. For C, Find how many meters is 1 centimeter, the answer is 1 cm : 12m, the meter is not bigger than 12, but the same, so C is wrong. For D, divide both sides by 3 to find 1 CM, the answer is 1 cm : 5 m, it is wrong.