ACT Math 4.1 Trigonometry
ACT Math: Trigonometry Drill 4, Problem 1. Simplify the expression.
|Foreign Language||Arabic Subtitled|
|Geometry||Right Triangles and Trigonometry|
|Product Type||ACT Math|
|Trigonometry||Solving trigonometric equations|
the fourth alpha as sine squared alpha squared
minus cosine squared alpha squared... because they're the same thing.
Now we need to call on our good friend - the
difference of two squares formula: x squared minus y squared equals x minus y times x plus y.
If we pretend that sin squared alpha is x
and cos squared alpha is y, we can simplify it to:
sin squared alpha minus cosine squared alpha times sin squared alpha PLUS cosine squared
alpha. We also know that (sin2⍺
+ cos2⍺) = 1 from the fundamental trig identities.
Now all we're left with is (sin2⍺ -- cos2⍺)...
...which happens to be answer D.