Question #a2179

2 Answers
Oct 10, 2015

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

Oct 10, 2015

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.