Question

sec square theta +tan square theta =7 , find the value of theta.

Answer 1

sec²@+tan²@=7,...........eq(1),

since

sec²@-tan²@=1,............eq(2),

now adding eq(1) and eq(2), we get

2sec²@=8,

sec²@=4,

then

sec@=√4,

sec@=2,

sec@=sec60°,

then

@=60°

Answer 2

Sec²x+tan²x=7

And there is a identity.

sec²x- tan²x=1

Subtract both formula

2tan²x=6

tan²x=3

tanx=√3

Hence x=60°