Area enclosed by sine and cosine.

[linuxux]

Homework Statement

Hello, I'm trying to find the area enclosed by sine the cosine function on the interval 45 degrees and 225 degrees, my problem is i get a negative number after i do the integration, my answer is -2 root 2.

here's what i did,

sin(x)-cos(x)dx

after integrating,

cos(x)+sin(x)

evaluating between 45 degrees and 225 degrees,

cos(225)+sin(225) - cos(45)-sin(45) (all of which equal -2 root 2 over 2)

resulting in -4 root 2 over 2 or, -2 root 2

 

[happyg1]

look at the graph

 

[Dick]

Your signs are wrong on the integral. Eg. the integral of sin(x) is -cos(x).

 

[linuxux]

oh, darn, i was looking going in a derivative direction (now i feel like i wasted 2 hours) thanks!