2007-01-21 12:58:13 · 4 answers · asked by fredgg78 1 in Science & Mathematics ➔ Mathematics
What's the reciprocal of sec x? That's what 1/(sec x) means and 1/(sec^2x) is just the square of that. Plug that in and a familiar identity will stare you in the face.
Addendum: Of course other answerers have stared this identity in your face for you already. Try to figure it out yourself and then come back to their answers to check your work. That's the way you learn.
2007-01-21 13:03:01 · answer #1 · answered by alnitaka 4 · 0⤊ 0⤋
sin^2x+(1/sec^2x)= sin^2x+cos^2x= 1. If you need proof of the last step, take a radius of the unit circle with angle x from the positive x-axis. The height of the right triangle generated by this radius is sinx and the base is cosx, so sin^2x+cos^2x=1.
2007-01-21 21:03:56 · answer #2 · answered by XelaleX 2 · 0⤊ 0⤋
sin^2x+(1/sec^2x)=1
sin^2 x+cos^2 x=1
1=1
2007-01-21 21:01:59 · answer #3 · answered by yupchagee 7 · 0⤊ 0⤋
1/sec^2 = cos^2.
sin^2 + cos^2 = 1
This is the pythagorean identity
2007-01-21 21:01:36 · answer #4 · answered by davidosterberg1 6 · 0⤊ 0⤋