Trigonometric Ratios?

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It says:
Find sec(-a) in terms of cos(a).

I know seca=1/cosa...but is that really all I need to do?

2007-01-17 20:54:43 · 3 answers · asked by Ken 2 in Science & Mathematics ➔ Mathematics

The secant is the reciprocal of the cosine for any argument:

sec(-a) = 1 / cos(-a)

because cos(-a) = cos(a)

sec(-a) = 1 / cos(a)

2007-01-17 21:28:15 · answer #1 · answered by schmiso 7 · 0⤊ 0⤋

assuming: sec(a) = 1/cos(a) then sec(-a) = 1/cos(-a) = 1/cos(a)

me things. ( cos is symmetrical cos(a) = cos(-a))

2007-01-17 21:01:31 · answer #2 · answered by Anonymous · 0⤊ 0⤋

Is it sec (a) or sec (-a) ?????

2007-01-17 20:59:05 · answer #3 · answered by Michael Kevin 3 · 0⤊ 0⤋