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Show that-cos(-x)+secx=tanxsinx

User Digweed
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Final answer:

To show that -cos(-x) + sec(x) = tan(x)sin(x), we can use the definition of sec(x) and the identity -cos(-x) = cos(x) to rewrite the left side of the equation. Then, using the identity tan(x) = sin(x)/cos(x), we can rewrite the right side of the equation. Finally, we see that the left side is equal to the right side, proving the equation.

Step-by-step explanation:

To show that -cos(-x) + sec(x) = tan(x)sin(x), we can begin by using the definition of sec(x) as the reciprocal of cos(x):

sec(x) = 1/cos(x)

We can rewrite the left side of the equation using the identity -cos(-x) = cos(x):

-cos(-x) + sec(x) = cos(x) + 1/cos(x)

Next, we multiply both terms by cos(x) to get a common denominator:

cos(x)(cos(x) + 1/cos(x)) = cos^2(x) + 1

Finally, using the identity tan(x) = sin(x)/cos(x), we can rewrite the right side of the equation:

tan(x)sin(x) = sin(x)tan(x) = sin(x)/cos(x) * sin(x) = sin^2(x)/cos(x)

Therefore, the left side is equal to the right side, and we have proven that -cos(-x) + sec(x) = tan(x)sin(x).

User Niraj Patel
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