Anja is creating a triangle using three straws. The two shorter straws have lengths of 20 cm and 21 cm. How long, in centimeters
1 answer:
You might be interested in
Part (c)
We'll use this identity
to say
Similarly,
-------------------------
The key takeaways here are that
Therefore,
The identity is confirmed.
==========================================================
Part (d)
Similarly,
-----------------
We'll square each equation
and
--------------------
Let's compare the results we got.
Now if we add the terms straight down, we end up with on the left side
As for the right side, the sin(A)cos(A) terms cancel out since they add to 0.
Also note how and similarly for the sin^2 terms as well.
The right hand side becomes but that's always equal to 1 (pythagorean trig identity)
This confirms that is an identity