# Point of intersection

• Aug 14th 2009, 10:50 AM
sun1
Point of intersection
What is the point of intersection between the curves y=sec²x and y=4?
I need it in order to find the area of the region bounded by the two curves.

Thanks.
• Aug 14th 2009, 10:59 AM
earboth
Quote:

Originally Posted by sun1
What is the point of intersection between the curves y=sec²x and y=4?
I need it in order to find the area of the region bounded by the two curves.

Thanks.

The y-values must be equal:

$\sec^2(x)=4$

$|\sec(x)|=2$

$\left|\dfrac1{\cos(x)}\right|=2$

$\cos(x) = -\dfrac12~\vee~\cos(x)=\dfrac12$

Can you take it from here?