I guess you mean the derivative of:
√7x + √2x, if so then:
Remember that the derivative of √u = 1/(2√u) . u'
if 7x = u, then u' = 7 , hence the derivative of √7x is 7/(2√7x)
Use same logic for √2x and you will find:
y' = 7/(2√7x) + x/√2x
Answer:
Andrew's test score if he got 8 questions wrong = 64 points
Andrew's test score if he got x questions wrong = 80 - 2x
Step-by-step explanation:
Total points of the multiple choice test = 80
Each question = 2 points
Total questions = Total points of the multiple choice test / 2 points
= 80/2
= 40
Total questions = 40
A. What would be Andrew's test score (out of 80) if he got 8 questions wrong
If he got 8 questions wrong out of 40 questions
= Total question points - wrong question points
= 40*2 - 8*2
= 80 - 16
= 64 points
Andrew's test score if he got 8 questions wrong = 64 points
B. What would be his score if he got x questions wrong?
Test points if he got x questions wrong = Total question points - wrong question points
= (40 * 2) - (x * 2)
= 80 - 2x
Andrew's test score if he got x questions wrong = 80 - 2x
Answer:
Answer is in the attachment
Step-by-step explanation:
Answer:
![\boxed{x=8y^2-16y-68}](https://tex.z-dn.net/?f=%5Cboxed%7Bx%3D8y%5E2-16y-68%7D)
Step-by-step explanation:
Hello, please consider the following.
![x=8(y- 1)^2-76\\\\x=8(y^2-2y+1)-76\\\\x=8y^2-16y+8-76\\\\\boxed{x=8y^2-16y-68}](https://tex.z-dn.net/?f=x%3D8%28y-%201%29%5E2-76%5C%5C%5C%5Cx%3D8%28y%5E2-2y%2B1%29-76%5C%5C%5C%5Cx%3D8y%5E2-16y%2B8-76%5C%5C%5C%5C%5Cboxed%7Bx%3D8y%5E2-16y-68%7D)
Hope this helps.
Do not hesitate if you need further explanation.
Thank you
![x_{1,2} = \frac{-b+- \sqrt{ b^{2} -4ac} }{2a}](https://tex.z-dn.net/?f=%20x_%7B1%2C2%7D%20%3D%20%20%5Cfrac%7B-b%2B-%20%20%5Csqrt%7B%20b%5E%7B2%7D%20-4ac%7D%20%7D%7B2a%7D%20%20)
is the formula for calculating x1 and x2
To prove x1 + x2 = -b/a all we need to do is to express x1 and x2 from equation above
once we do we will get -2b/2a which is equal to -b/a because square root part will negate each other. one has + sign in front and other - sign
Showing that x1x2 = c/a goes similar way.
the numerator parts is actually difference of squares. after that we will have:
-b^2 -b^2 + 4ac = 4ac
in denominator we have 2a*2a = 4a^2
4ac/4aa = c/a