Given f(x) = 2x² + 4x -3, find f(3). thanks
can u also help me with another question which is:
5m² +8m + 1 = 0
i have to use the x= -b√b² - 4ac / 2a
thnx
can u also help me with another question which is:
5m² +8m + 1 = 0
i have to use the x= -b√b² - 4ac / 2a
thnx
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f(3)=27
Just plug the 3 in where all the x's are and solve (use the order of operations)
x= -4+√11/ 5
x= -4-√11/ 5
This question had me stuck for a second because I was making sure I was 100% correct. I used this formula (am^+bm+c=0) = (5m² +8m + 1 = 0) to plug in the numbers in the quadratic equation. Then I simplified the square root by multiplying 4x(a)x(c) and subtracted that from b^ (^=2). Then I went outside the square root and saw that the numerator (-b) and the denominator (2a) were both divisible by 2 and simplified the fraction. The answer cannot be simplified anymore giving you the answers above.
Addition: You may ask what happened to the 2 when you simplify √44 and get 2√11, the 2 becomes a 1 when you divide the numerator and the denominator by the GCF (Greatest Common Factor) and is still there but doesn't have to be shown.
These answers are 100% correct. I guarantee you.
Hope this was helpful. Vote as Best Answer, other answers could be wrong or copies of this answer.
My answer really isn't this new, I just keep editing it to give you more information on how I got the answer.
Just plug the 3 in where all the x's are and solve (use the order of operations)
x= -4+√11/ 5
x= -4-√11/ 5
This question had me stuck for a second because I was making sure I was 100% correct. I used this formula (am^+bm+c=0) = (5m² +8m + 1 = 0) to plug in the numbers in the quadratic equation. Then I simplified the square root by multiplying 4x(a)x(c) and subtracted that from b^ (^=2). Then I went outside the square root and saw that the numerator (-b) and the denominator (2a) were both divisible by 2 and simplified the fraction. The answer cannot be simplified anymore giving you the answers above.
Addition: You may ask what happened to the 2 when you simplify √44 and get 2√11, the 2 becomes a 1 when you divide the numerator and the denominator by the GCF (Greatest Common Factor) and is still there but doesn't have to be shown.
These answers are 100% correct. I guarantee you.
Hope this was helpful. Vote as Best Answer, other answers could be wrong or copies of this answer.
My answer really isn't this new, I just keep editing it to give you more information on how I got the answer.
-
Solving for x = 3 you have:
2 * 3² + 4*3 -3 = 18 + 12 -3 = 27
From the general equation am² + bm + c = 0, a = 5, b = 8, c = 1
x = (-8 + √(64-4*5*1))/10 or x = (-8 - √(64-4*5*1))/10
x = (√11 - 4) / 5 or x = (-√11 - 4) / 5
x = -0.137 or x = -1.46 to 3 significant figures
2 * 3² + 4*3 -3 = 18 + 12 -3 = 27
From the general equation am² + bm + c = 0, a = 5, b = 8, c = 1
x = (-8 + √(64-4*5*1))/10 or x = (-8 - √(64-4*5*1))/10
x = (√11 - 4) / 5 or x = (-√11 - 4) / 5
x = -0.137 or x = -1.46 to 3 significant figures
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simply substitute 3 in to 2x^2+4x-3, or 2(3)^2+4(3)-3, or 18+12-3, or 27.
For the bottom, let us first find the discriminant, sqr(8^2 - 4*5*1), which is sqr(44) or 2sqr(11).
So now (with simplification) we have -4+sqr(11) / 5 and -4-sqr(11) / 5. When m is 0.
For the bottom, let us first find the discriminant, sqr(8^2 - 4*5*1), which is sqr(44) or 2sqr(11).
So now (with simplification) we have -4+sqr(11) / 5 and -4-sqr(11) / 5. When m is 0.