Step by step
The question
Question: simplify sin x × sec x.
Simplify means: write it as simply as we can.
sin x × sec x
1 Write in sin and cos
Everything is easier in sin and cos.
sec is 1 over cos.
sec x = 1cos x
We put them in.
Tops go on top, bottoms at the bottom.
= sin xcos x
2 Name it
sin x over cos x has its own name: tan x.
= tan x
So it simplifies to tan x.
3 Check
Let's check with a number: x = 30°.
On the calculator, sin 30° × sec 30° is about 0.5774.
x = 30°: sin 30° × sec 30° ≈ 0.5774
And tan 30° is about 0.5774.
The same!
So it is right.
tan 30° ≈ 0.5774
Let's look back.
First: write in sin and cos.
Then: name it.
Last: check.
Answer
= tan x