June 2019 archive

Week 17 – Precalc 11

This week in pre-calculus we started our unit on trigonometry. We learned about Sine Law, it’s an equation on how to find the sides and the angles in a triangle all put into one instead of having to use separate equations to solve. If we’re solving for a side of the triangle we’ll use the ratio \frac {a}{sinA} = \frac {b}{sinB} = \frac {c}{sinC} .

If we want to solve for the angle then we reciprocate the ratio and it’ll be \frac{sinA}{a} = \frac{sinB}{b} = \frac{sinC}{c} .

To solve for side “a” then we’ll use the first equation.

ex/ \frac{a}{sin73}= \frac{12}{sin44}

once we rearrange and cross multiply we’ll get

a= \frac{sin(73)-12}{sin44} = 16.52

 

Week 16 – PreCalc 11

This week we learned about rational equations which are different from the expressions we have been doing, because now we need to solve for the variable. Two ways to do this is by cross multiplying or by multiplying by the common denominator.

Here is an example of cross multiplying to solve for the variable: