ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
ACT Math Videos 161 videos
ACT Math: Plane Geometry Drill 3, Problem 1. What is the area of the trapezoid shape in the video?
ACT Math Pre-Algebra Drill 2, Problem 5. Given the chart in the video, what is the mode?
ACT Math 5.1 Pre-Algebra 466 Views
Share It!
Description:
ACT Math: Pre-Algebra Drill 5, Problem 1. Factoring in depreciation, how much is the car worth?
Transcript
- 00:02
And here is your shmoop de jour.
- 00:04
Simplified tangents squared alpha over sine squared alpha minus 1
- 00:10
And here are the potential answers...
- 00:14
Okay well whenever we see a tangent we can change
- 00:18
to sine over cosine. Now we have a triple layer fraction cake.
Full Transcript
- 00:23
To get rid of it, we multiply by one over sin squared alpha
- 00:28
The sines squared alpha cancels out on the top and bottom like this
- 00:31
which leaves us with one over cosine squared alpha -1
- 00:36
cosine and secant are inverse functions
- 00:39
so 1 over cosine squared alpha is the same thing
- 00:43
as secant squared alpha and the handy dandy trig identity
- 00:46
1 plus tangent squared alpha equals secant squared alpha
- 00:49
can be rearranged to become secant squared alpha -1
- 00:53
equals tangent squared alpha. What do you know? We're left with secant squared alpha
- 00:57
-1 in our expression
- 00:59
and we just figured out secant squared alpha -1 equals tangent squared alpha.
- 01:04
Which is option E.
Related Videos
ACT Math: Plane Geometry Drill 3, Problem 1. What is the area of the trapezoid shape in the video?
ACT Math: Coordinate Geometry Drill 1, Problem 1. Which inequality is expressed by the number line?
ACT Math: Intermediate Algebra: Drill 3, Problem 1. Find the fifth number in the series.
SAT Math 10.3 Geometry and Measurement. What is the ratio of birds to dogs?
SAT Math 2.1 Statistics and Probability. Which two items have the highest protein to fat ratio?