Hello, McScruffy!
Your area formula is the best one to use.
Don't forget to convert all angles to radians.
Given the problem:
Two sides of a triangle measure 9 in. and 6 in. The measure of the inclusive angle changes from to . Use differentials to approximate the change in the area of the triangle.
I used , where a and b are the lengths of the sides and C is the included angle, for my area function. I am just wondering if anyone has another approach for the area equation that would work well with this problem.
Thanks
Start from the first principles defination. The various trig limits (that you've probably taken for granted as standard forms) are found using radian measure. Google will turn up relevant pages. And there's an old thread somwehere that discusses the derivation of using a geometric approach ....
Say no more. I'm very familiar with the proof. I now can see why the use radians was so covienient. It is because the area sector of the portion of the unit circle is squeezed between the two triangles as the angle tends to zero. Right? And using radians, the area sector is simply . Is this right or wrong?