Thread: FInd exact value of the expression Sec(arctan -5/12)

Hey guys i want to know if i am correct here

let y=arctan(-5/12)

sec y= 13/12 or 65 degrees

is this correct

Yep, except you might not want the 65 degrees as your answer as that is obviously not an exact answer and is not even equivalent to your expression.

should be unitless.

Originally Posted by NoAsherelol

Hey guys i want to know if i am correct here

let y=arctan(-5/12)

sec y= 13/12 or 65 degrees

is this correct

The correct answer is NOT an angle .....

OR .

Originally Posted by NoAsherelol

Hey guys i want to know if i am correct here

let y=arctan(-5/12)

sec y= 13/12 or 65 degrees

is this correct

Originally Posted by NoAsherelol

Hey guys i want to know if i am correct here

let y=arctan(-5/12)

sec y= 13/12 or 65 degrees

is this correct

If y = arctan(-5 /12),
then, tan(y) = -5/ 12
So, y is an angle whose tan value is -5 /12.

tan = (opposite side)/(adjacent side) = opp/adj

So, for angle y above,
opp = -5
adj = 12
The hypotenuse---hyp---then is sqrt[(-5)^2 +(12)^2] = 13

sec = hyp/adj
So, sec(y) = 13/12 -----you got that right.

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If y = arctan(5/(-12)),
Then, opp = 5, adj = -12, hyp = 13

sec(y) = 13/(-12) or -(13/12)