D, it increases then goes at a constant speed
Step-by-step explanation:
vv
The answer is 7(x+5) ive had the exact question before!! Hope i helped u!!!!
1/9 = 0.1111111111...
That's a repeating decimal because the 1 repeats over and over again.
1/3 = 0.33333333...
That's a repeating decimal because the 3 repeats over and over again.
Have an awesome day! :)
Let point P be with coordinates
Find the equation of the tangent line.
1. If
then ![y'=-2x.](https://tex.z-dn.net/?f=y%27%3D-2x.)
2. The equation of the tangent line at point P is
![y-y_0=-2x_0(x-x_0).](https://tex.z-dn.net/?f=y-y_0%3D-2x_0%28x-x_0%29.)
Find x-intercept and y-intercept of this line:
- when x=0, then
![y=y_0+2x_0^2;](https://tex.z-dn.net/?f=y%3Dy_0%2B2x_0%5E2%3B)
- when y=0, then
![x=\dfrac{y_0}{2x_0}+x_0=\dfrac{y_0+2x_0^2}{2x_0}.](https://tex.z-dn.net/?f=x%3D%5Cdfrac%7By_0%7D%7B2x_0%7D%2Bx_0%3D%5Cdfrac%7By_0%2B2x_0%5E2%7D%7B2x_0%7D.)
The area of the triangle enclosed by the tangent line at P, the x-axis, and y-axis is
![A=\dfrac{1}{2}\cdot (2x_0^2+y_0)\cdot \left(\dfrac{y_0+2x_0^2}{2x_0}\right)=\dfrac{(y_0+2x_0^2)^2}{4x_0}.](https://tex.z-dn.net/?f=A%3D%5Cdfrac%7B1%7D%7B2%7D%5Ccdot%20%282x_0%5E2%2By_0%29%5Ccdot%20%5Cleft%28%5Cdfrac%7By_0%2B2x_0%5E2%7D%7B2x_0%7D%5Cright%29%3D%5Cdfrac%7B%28y_0%2B2x_0%5E2%29%5E2%7D%7B4x_0%7D.)
Since point P is on the parabola, then
and
![A=\dfrac{(1-x_0^2+2x_0^2)^2}{4x_0}=\dfrac{(1+x_0^2)^2}{4x_0}.](https://tex.z-dn.net/?f=A%3D%5Cdfrac%7B%281-x_0%5E2%2B2x_0%5E2%29%5E2%7D%7B4x_0%7D%3D%5Cdfrac%7B%281%2Bx_0%5E2%29%5E2%7D%7B4x_0%7D.)
Find the derivative A':
![A'=\dfrac{2(1+x_0^2)\cdot 2x_0\cdot 4x_0-4(1+x_0^2)^2}{16x_0^2}=\dfrac{12x_0^4+8x_0^2-4}{16x_0^2}.](https://tex.z-dn.net/?f=A%27%3D%5Cdfrac%7B2%281%2Bx_0%5E2%29%5Ccdot%202x_0%5Ccdot%204x_0-4%281%2Bx_0%5E2%29%5E2%7D%7B16x_0%5E2%7D%3D%5Cdfrac%7B12x_0%5E4%2B8x_0%5E2-4%7D%7B16x_0%5E2%7D.)
Equate this derivative to 0, then
![12x_0^4+8x_0^2-4=0,\\ \\3x_0^4+2x_0^2-1=0,\\ \\D=2^2-4\cdot 3\cdot (-1)=16,\ \sqrt{D}=4,\\ \\x_0^2_{1,2}=\dfrac{-2\pm4}{6}=-1,\dfrac{1}{3},\\ \\x_0^2=\dfrac{1}{3}\Rightarrow x_0_{1,2}=\pm\dfrac{1}{\sqrt{3}}.](https://tex.z-dn.net/?f=12x_0%5E4%2B8x_0%5E2-4%3D0%2C%5C%5C%20%5C%5C3x_0%5E4%2B2x_0%5E2-1%3D0%2C%5C%5C%20%5C%5CD%3D2%5E2-4%5Ccdot%203%5Ccdot%20%28-1%29%3D16%2C%5C%20%5Csqrt%7BD%7D%3D4%2C%5C%5C%20%5C%5Cx_0%5E2_%7B1%2C2%7D%3D%5Cdfrac%7B-2%5Cpm4%7D%7B6%7D%3D-1%2C%5Cdfrac%7B1%7D%7B3%7D%2C%5C%5C%20%5C%5Cx_0%5E2%3D%5Cdfrac%7B1%7D%7B3%7D%5CRightarrow%20x_0_%7B1%2C2%7D%3D%5Cpm%5Cdfrac%7B1%7D%7B%5Csqrt%7B3%7D%7D.)
And
![y_0=1-\left(\pm\dfrac{1}{\sqrt{3}}\right)^2=\dfrac{2}{3}.](https://tex.z-dn.net/?f=y_0%3D1-%5Cleft%28%5Cpm%5Cdfrac%7B1%7D%7B%5Csqrt%7B3%7D%7D%5Cright%29%5E2%3D%5Cdfrac%7B2%7D%7B3%7D.)
Answer: two points: ![P_1\left(-\dfrac{1}{\sqrt{3}},\dfrac{2}{3}\right), P_2\left(\dfrac{1}{\sqrt{3}},\dfrac{2}{3}\right).](https://tex.z-dn.net/?f=P_1%5Cleft%28-%5Cdfrac%7B1%7D%7B%5Csqrt%7B3%7D%7D%2C%5Cdfrac%7B2%7D%7B3%7D%5Cright%29%2C%20P_2%5Cleft%28%5Cdfrac%7B1%7D%7B%5Csqrt%7B3%7D%7D%2C%5Cdfrac%7B2%7D%7B3%7D%5Cright%29.)