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In ABC, m∠ A=x²+12, m∠ B=11x+5 , and m∠ C=13x-17. Determine the longest side of ABC. x= -b± √b²-4ac/2a

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The longest side of triangle ABC is opposite angle C, and the corresponding expression is 13x - 17.

To determine the longest side of triangle ABC, we can use the Law of Cosines. The Law of Cosines relates the lengths of the sides of a triangle to the cosine of one of its angles. For a triangle with sides a, b, and c, and an angle C opposite side c, the Law of Cosines is given by:

c^2 = a^2 + b^2 - 2ab * cos(C)

In this case, we need to find the longest side, so we are interested in the side opposite the largest angle. Let's find the angle measures first:

m∠A = x^2 + 12

m∠B = 11x + 5

m∠C = 13x - 17

Now, to find the longest side, we need to find the maximum value among these angle measures. Taking derivatives of each expression with respect to x and setting them equal to zero can help find critical points. However, this may lead to complex solutions.

Alternatively, we can compare the coefficients of x in each expression. The angle with the largest coefficient of x tends to dominate as x becomes large. Therefore, the longest side is likely opposite the angle with the largest coefficient.

Comparing the coefficients:

x^2 + 12 (Coefficient of x^2: 1)

11x + 5 (Coefficient of x: 11)

13x - 17 (Coefficient of x: 13)

Therefore, m∠C = 13x - 17 has the largest coefficient of x, and the longest side is likely opposite angle C.

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