If 
begin mathsize 20px style cos to the power of negative 1 end exponent alpha plus cos to the power of negative 1 end exponent beta plus cos to the power of negative 1 end exponent gamma equals 3 straight pi comma then space
straight alpha open parentheses straight beta plus straight gamma close parentheses plus straight beta open parentheses straight gamma plus straight alpha close parentheses plus straight gamma open parentheses straight alpha plus straight beta close parentheses equal colon
straight i.0 space space space ii.1 space space space iii.6 space space space iv.12 end style

Asked by sunil2791 | 8th Jul, 2017, 07:48: PM

Expert Answer:

begin mathsize 16px style cos to the power of negative 1 end exponent alpha plus cos to the power of negative 1 end exponent beta plus cos to the power of negative 1 end exponent gamma equals 3 straight pi
rightwards double arrow cos to the power of negative 1 end exponent straight alpha equals cos to the power of negative 1 end exponent straight beta equals cos to the power of negative 1 end exponent straight gamma equals straight pi
rightwards double arrow straight alpha equals straight beta equals straight gamma equals cosπ equals negative 1
straight alpha open parentheses straight beta plus straight gamma close parentheses plus straight beta left parenthesis straight alpha plus straight gamma right parenthesis plus straight gamma left parenthesis straight alpha plus straight beta right parenthesis equals negative 1 open parentheses negative 1 minus 1 close parentheses minus 1 open parentheses negative 1 minus 1 close parentheses minus 1 open parentheses negative 1 minus 1 close parentheses
equals 6 end style

Answered by Sneha shidid | 8th Jul, 2017, 09:50: PM