Solve using the quadratic formula.y2−6y−9=0Write your answers as integers, proper or improper fractions in simplest form, or decimals rounded to the nearest hundredth.y=_____ or y=_____
Q. Solve using the quadratic formula.y2−6y−9=0Write your answers as integers, proper or improper fractions in simplest form, or decimals rounded to the nearest hundredth.y=_____ or y=_____
Identify Coefficients: Identify the coefficients of the quadratic equationy2−6y−9=0 by comparing it to the standard form ax2+bx+c=0. Here, a=1, b=−6, and c=−9.
Substitute Values: Substitute the values of a, b, and c into the quadratic formula, which is y=2a−b±b2−4ac.So we have y=2⋅1−(−6)±(−6)2−4⋅1⋅(−9).
Calculate Discriminant: Simplify the equation by calculating the discriminant (the part under the square root) first: (−6)2−4⋅1⋅(−9)=36+36=72.
Substitute Discriminant: Now, substitute the discriminant back into the quadratic formula: y=26±72.
Simplify Square Root: Simplify the square root of 72. Since 72=36×2 and the square root of 36 is 6, we have 72=36×2=6×2.
Substitute Simplified Square Root: Substitute the simplified square root back into the equation: y=26±6×2.
Divide by 2: Divide both terms in the numerator by 2 to simplify the equation: y=23±3×2.
Calculate Approximate Values: Calculate the approximate decimal values of y by evaluating both the positive and negative cases, rounding to the nearest hundredth if necessary.For the positive case: y≈3+3×1.41≈3+4.23≈7.23.For the negative case: y≈3−3×1.41≈3−4.23≈−1.23.
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