cossquare20 + cossquare70 / 2(sinsquare59 + sinsquare31) =2/k then find k.
Options are-
a. 1
b. 2
c. 3 
d. 4

Asked by Sthitaprajna Mishra | 28th Aug, 2014, 10:33: PM

Expert Answer:

fraction numerator cos space squared space 20 space plus space cos space squared space 70 over denominator 2 open parentheses sin space squared space 59 space plus thin space sin space squared space 31 close parentheses end fraction equals 2 over k  20 equals space 90 minus 70 space rightwards double arrow space cos space 20 space equals space sin space 70 59 equals 90 minus 31 space rightwards double arrow space sin space 59 space equals space cos space 31   fraction numerator cos space squared space 20 space plus space cos space squared space 70 over denominator 2 open parentheses sin space squared space 59 space plus thin space sin space squared space 31 close parentheses end fraction equals fraction numerator sin space squared space 70 space plus cos space squared space 70 thin space over denominator 2 open parentheses cos squared space 31 plus space thin space sin space squared space 31 close parentheses end fraction equals 1 half equals 2 over 4 equals 2 over k  S o space k equals 4

Answered by Dharma Teja | 30th Aug, 2014, 01:11: AM