Plz solve ques 51 urgently

Asked by lovemaan5500 | 14th Jan, 2018, 02:18: PM

Expert Answer:

begin mathsize 16px style left parenthesis straight i right parenthesis
sec squared straight theta minus 2 tanθ equals 0
Using space sec squared straight theta equals 1 plus tan squared straight theta
1 plus tan squared straight theta minus 2 tanθ equals 0
Let space tanθ equals straight x
1 plus straight x squared minus 2 straight x equals 0
left parenthesis straight x minus 1 right parenthesis squared equals 0
straight x minus 1 equals 0
straight x equals 1
tanθ equals 1
straight theta equals 45 degree

left parenthesis iii right parenthesis
2 cos 3 straight theta equals 1
cos 3 straight theta equals 1 half
3 straight theta equals 60 degree
straight theta equals 20 degree
end style

Answered by Sneha shidid | 16th Jan, 2018, 09:44: AM