Question

Question #a2179

Answer 1

Samina - the first in an inverse trig function while the latter is reciprocal of `cos(x)`

Explanation:

The argument "x" for `cos^-1(x)` will always be the ratio of adjacent over hypotenuse. For example:

`cos^-1(1/2)= 60^o`

In other words for a right triangle, `cos(60^o)=1/2` so the inverse of this is simply `cos^-1(1/2)= 60^o`

For the latter using the same example, `1/cos(x)`:

`1/cos(60^o)=1/(1/2)= 2=sec(60)`

Hope that helped

Answer 2

They are very different.

Explanation:

1/cos(x) is simply sec(x) which gives the value of sec(x) (a real number) for a given x (an angle). But cos^-1(x) gives the value of x if you already know the value of cos(x). It,s somewhat like log and antilog.