If you look at the graphs, you can see that they are different by a phase angle of pi/2. You can also use the equation for sin(A+B) …

Continue Reading about “Why is it that sin(θ+π/2)=cos(θ) for all angles θ?” →

If you look at the graphs, you can see that they are different by a phase angle of pi/2. You can also use the equation for sin(A+B) …

Continue Reading about “Why is it that sin(θ+π/2)=cos(θ) for all angles θ?” →

We started by looking at the cosine functions of sums and differences. Then used the Pythagorean Theorem on some triangles for some problems using the equations. Fractional exponents like 1/2 …

Continue Reading about Tutoring Math at RLS, Friday Sheet in April →

Apparently TI calculators use the CORIDC algorithm which involves rotation on a complex plane using complex numbers. COordinate Rotation DIgital Computer aka Voldic’s algorithm I would …

Continue Reading about What does your calculator do when you press the sin/cos/tan button? →

By Neal 2 Comments

We started by looking at evaluating trig functions of angles. They involved 30 60 90 triangles and 45 45 90. So we began by looking at those triangles. It's easy enough to derive the ratios for the …

Saw this question today, If you take the trig function of two different values, the results could be equal, but there is no reason they have to be. In this case, the two results are not equal. …

I’ve drawn a triangle that has an angle close to 90°, it’s looks more like 85°. That is to make it look like a triangle rather than a degenerate triangle (straight line). But I have used the values of …