Is arccos the same as sec?

Hi,

If sec is 1/cos then does this mean that arccos is the same as sec???

Reply 1

No. arccos(cos(x)) = x, whereas sec(x)*cos(x) = 1

Reply 2

faa

Hi,

If sec is 1/cos then does this mean that arccos is the same as sec???

secx = (cosx)^-1 = 1/cosx
arc(cosx) = cos^-1(x) (Inverse of cos x)

So no.

Reply 3

Confusing reciprocal and inverse?

Reply 4

Reciprocal being sec and inverse being arccos, yeh?

Reply 5

yeah so you have
f^-1(x) =/= 1/f(x)
where f is sin, cos or tan

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