Simplify (1 − sin x)(1 + sin x).

Question

asked Feb 28, 2017 127k views

2 Answers

Andrsnn · Answer 1 · 2017-02-28T13:50:19+0000

Answer:

$(1-\sin x )(1+\sin x)=\cos^2x$

Explanation:

Given : Expression
$(1-\sin x )(1+\sin x)$

To find : Simplify the expression ?

Solution :

Step 1 - Write the expression,

$(1-\sin x )(1+\sin x)$

Step 2 - Applying identity,
(a+b)(a-b)=a^2-b^2

$(1-\sin x )(1+\sin x)=1^2-\sin^2x$

$(1-\sin x )(1+\sin x)=1-\sin^2x$

Step 3 - Applying trigonometric identity,
$\sin^2x+\cos^2x=1$

$(1-\sin x )(1+\sin x)=\cos^2x$

Therefore,
$(1-\sin x )(1+\sin x)=\cos^2x$

Chunjw · Answer 2 · 2017-03-04T07:23:31+0000

Finally...

(1-sin x )(1+sin x )

Now we have (1-sin(x)) (1+sin(x))

There is something call Expanded which is the way to write numbers by showing the value of each digit (google)

So let's us it to see what we find.

(1-sin(x)) (1+sin(x) that's equal 1-sin²(x)

We knew that 1-sin²(x) = cos²(x)

Answer : Cos²(x)

wow I did it guys :))

Hey I hope its help XD