If the image vertex of the quadratic function y = 2x2 + 4x + C is on the X axis, what is C equal to …………
Method 1)
y=2x²+4x+c=2(x²+2x)+c=2(x+1)²+c-2
So C-2 = 0, that is, C = 2
Method 2)
Discriminant
=△
=b^2-4ac
=16-4×2c=0,
The solution is C = 2
RELATED INFORMATIONS
- 1. To find the functional relation y = ax & # 178; - 1 of parabola y = ax & # 178;, the opening size is the same, but the direction is opposite
- 2. Parabola y = ax & # 178; through point (2, - 2) to find the function relation, when x is the value, y increases with the increase of X
- 3. Given the square of the parabola y = ax + BX + C, where / A / = 2, and the coordinates of the lowest point (- 1,3) (1), find the functional relation of the parabola (2) Find the coordinates of the intersection of the line y = 2x + 9 and the parabola
- 4. When the value of x increases from 0 to 2, the value of the function decreases by 4, then the analytic expression of the parabola y = ax & # 178; - 1 is?
- 5. If the quadratic equation MX & sup2; - 2x-1 = 0 with respect to X has no real root, then the image of the linear function y = (M + 1) x-m does not pass through which image
- 6. If the quadratic equation x ^ 2-2x-m = 0 has no real root, then the image of the linear function y = (M + 1) x + M-1 does not pass through the quadrant
- 7. Prove that the function y = x & # / x-3, (1 ≤ x ≤ 2) is a decreasing function rt
- 8. The number of intersections between the image of function y = (X & # 178; - 2x) 178; - 9 and X axis is
- 9. The set of intersection points between the image of function y = x + 1 and the image of function y = x * 2 + a (constant a ∈ R) is represented by enumeration
- 10. It is proved that the function y = 1 / X & # 178; is bounded on (1,2)
- 11. [calculus problem] given the function derivative and function value, find this function Find the function y = f (x). In the domain of definition (- π / 2, π / 2), the derivative is dy / DX = TaNx and satisfies the condition that f (3) = 5 The answer is: F (x) = ∫ (upper x, lower 3) tank DT + 5 My question: how is the upper and lower of ∫ determined? Why is the lower of ∫ 3? I thought the upper and lower of ∫ should be interval (here I think the upper and lower should be π / 2 and - π / 2) Great Xia, help to talk and guide maze! Thank you!
- 12. Finding the n-order derivative dny / DX ^ n of function y = ln (x ^ 2 + 3x + 2)
- 13. Let f (x) = x · ekx (K ≠ 0) ((ekx) ′ = kekx) (1) find the tangent equation of curve y = f (x) at point (0, f (0)); (2) find the monotone interval of function f (x)
- 14. Given the function f (x) = ln (1 + x) - x + K / 2 * x * x (k is not less than 0) (1) when k = 2, find the tangent equation of curve y = f (x) at point (1, f (1)) Which year's college entrance examination question is this? The second question is to find the monotone interval of F (x)
- 15. Find a point P on the parabola y ^ 2 = 4x, so that the distance from point P to the straight line y = x + 3 is the shortest
- 16. The monotonicity of function f (x) = 1 / 3x3 + ax & # 178; + X + 1 is discussed
- 17. Try to discuss the monotonicity of function f (x) = x x 2 + 1
- 18. What is the monotonicity of the function f (x) = x & # 178; - 2aX + 1?
- 19. Find the monotone interval of function f (x) = x / (X & # 178; + 1)
- 20. Finding monotone interval of function f (x) = - X & # 178; + A / X Urgent ah, know quickly recover The range of a is > 0