The Law of Cosines states (in this case): a^2 = b^2 + c^2 - 2 * b * c * cos A, where "a" is the side opposite angle A (7 inches), and b and c are the other two sides.

Plug the numbers in and you get: 7^2 = 5^2 + 9^2 - 2 * 5 * 9 * cos A, or:

49 = 25 + 81 - 90 * cos A.

Subtract (25 + 81) from both sides to get:

-57 = -90 * cos A.

Divide by -90 on both sides:

cos A = 19/30

To find A, you do the inverse trigonometric function to get:

cos^-1 of (19/30) = A.

I don't have a calculator that can do this right now, but if you plug the left side of the above equation into it (make sure it is in degrees, not radians), you should get A.

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3 years ago

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What is the slope of the line given by the equation y = -5x? Enter your answer as an integer or fraction in lowest terms. BTW ca

faust18 [17]

Answer:

slope = - 5

Step-by-step explanation:

given the equation of a line in the form

y = mx ← m is the slope

y = - 5x is in this form with slope m = - 5

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