Question
The value of cos² 10° + cos² 20° + cos² 30° +
……. + cos² 90° isSolution
ATQ, We know cos(90° - A) = sin A cos² 10 + cos² 20 + cos² 30° +……. + cos² 90° = cos² 1 + cos² 20 + cos² 30° + cos² 40° + sin² 40+ sin² 30° + sin² 20 + sin² 10+ cos² 90 = (sın² 10° + cos2 10) + (sin² 20 + cos² 20) + (sin² 30° + cos² 30) + (sin² 40+ cos² 40°) + cos² 90 = 1+1+1+1+0 = 4
What number should replace the question mark?Â
In each of the following questions select the related letter/word/figure/number from the given alternatives.
JRH : ? : : KOV : 51Â
Select the number from among the given option that can replace the question mark (?) in the following series.
6, 31, 126, 381, 766, ?
Study the given pattern carefully and select the number that can replace the question mark (?) in it.
First row: 14, 12, 108
Second row:...
Find the missing number?
What will come in the place of question mark?
Select the number from the given option that can replace the question mark (?) in the following series:
32, 16, 24, 60, ?, 945
Study the given matric carefully and select the number from among the given options that can replace the question mark (?) in it.
Select the option that is related to the third number in the same way as the second number is related to the first number.
15 : 5 :: 26 : (?)
Find the missing number by analysing the pattern followed by the numbers in each row.
