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Verify the identity (cos x )(tan x + sin x cot x) = sin x + cos2 x. Show all work for full credit.

User Icekomo
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Answer:

Explanation:

Starting with the left-hand side (LHS) of the identity:

(cos x)(tan x + sin x cot x)

We can simplify using trigonometric identities. First, we can rewrite tan x as sin x/cos x and cot x as cos x/sin x:

(cos x)(sin x/cos x + sin x(cos x/sin x))

Simplifying, we get:

(sin x + cos2 x)/sin x

Next, we can multiply the numerator and denominator by the conjugate of sin x + cos2 x, which is sin x - cos2 x:

[(sin x + cos2 x)/(sin x + cos2 x)] * [(sin x - cos2 x)/(sin x - cos2 x)]

Expanding and simplifying, we get:

[(sin x)(sin x - cos2 x) + (cos2 x)(sin x - cos2 x)] / [(sin x)(sin x - cos2 x) + (cos2 x)(sin x + cos2 x)]

Simplifying further, we get:

(sin2 x - cos2 x + cos2 x sin x - cos4 x) / (sin2 x + cos2 x)

Using the identity sin2 x + cos2 x = 1 and simplifying, we get:

(sin x - cos2 x) / 1

Finally, using the identity cos2 x = 1 - sin2 x, we can simplify to:

(sin x - (1 - sin2 x)) / 1

Simplifying further, we get:

2 sin x - 1

So the left-hand side is equal to 2 sin x - 1.

Now, let's simplify the right-hand side (RHS) of the identity:

sin x + cos2 x

Using the identity cos2 x = 1 - sin2 x, we can rewrite the RHS as:

sin x + 1 - sin2 x

Simplifying further, we get:

1 - sin2 x + sin x

Finally, using the identity sin2 x + cos2 x = 1, we can rewrite as:

cos2 x + sin x

So the right-hand side is equal to cos2 x + sin x.

Since the left-hand side is equal to 2 sin x - 1 and the right-hand side is equal to cos2 x + sin x, the identity is not true in general. Therefore, the given identity does not hold true.

hope this helps

User Tiia
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