If you can. i will give brainiest to best answer. this question is a calculus/trigonometry question. i ask that you look over my work, but if you don't have the time, i ask that you me answer the questions i don't know.

7 is incorrect. The answer should be -4. Here's how I'd derive it:

With , we should expect . If , then

Also,

so we should expect and

You seem to be taking

but this is not an identity.

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8 is incorrect. Just a silly mistake, you swapped the order of the terms in the numerator. It should be

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9. Use the identity from (7). lies in the second quadrant, so

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12.

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13.

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14.

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15.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.

irrational, then, just means all the numbers that aren't rational. every integer is a rational number, since each integer n can be written in the form n/1. however, numbers like 1/2, 45454737/2424242, and -3/7 are also rational, since they are fractions whose numerator and denominator are integers.

step-by-step explanation: