Today in Math!

Well today in math I actually listened. I am in Algebra II/Trigonometry and the Chapter we are studying is Analytic Trigonometry or in other terms; using sine, cosine, and tangent (and their inverses) to find functions, and evaluate to find certain terms.
Today we did 7.4 which is using sum and difference formulas of sine, cosine, and tangent to find the exact value of trigonometric functions of specified angles.
The formulas are:
sin(u+v)=sinucosv + cosusinv
sin(u-v)=sinucosv - cosusinv
cos(u+v)=cosucosv - sinusinv
cos(u-v)=cosucosv + sinusinv
tan(u+v)=(tanu + tanv)/(1 - tanutanv)
tan(u-v)=(tanu - tanv)/(1 + tanutanv)
Example:
cos75=cos(30 + 45) using the formula cos(u+v)=cosucosv - sinusinv, you input variables u and v
=cos30cos45 - sin30sin45 then find the values of the cosines and sines
=(√3/2)(√2/2)-(1/2)(√2/2) solve terms
=(√6-√2)/4

To find √3/2 and the other inputs we use the trigonometric table:


And that my friends, is what I learned today.