Sum and difference formulas

Question

cos[sin inverse(12/13) + cos inverse(-5/13)

how do i draw -5/13 what quadrant?

Answer 1

You problem is not complete, I assume the problem is .

Let’s set and ,

so we have: , and .

And the problem is to calculate

Since ,  is in quadrant 1 or 2; also since ,  is in quadrant 2 or 3.

1. if in quadrant 1, ; if in quadrant 2, ;
2. if in quadrant 2, ; if in quadrant 3, .

so, if in quadrant 1,  in quadrant 2: result -1;

if in quadrant 1,  in quadrant 3: result 119/169;

if in quadrant 2,  in quadrant 2: result -119/169;

if in quadrant 2,  in quadrant 3: result 1.

Answer 2

cos[sin inverse(12/13) + cos inverse(-5/13)

" ( asin.92307.......)+ acos-.3846...........

" 67.3801........ + 112.6198..........

.3846............. + " =113.0044............

Here's the problem; I don't know about plotting; there's no x or y.

Answer 3

The cos is neg in quadrant 4!

Draw a figure and you will see that you have 2 congruent triangles, one in quadrant 1 and the other in quadrant 4.

Technically, the sum of the angles is 0 and the cos is 1.