Perpendicular slope: 3
y + 7 = 3(x + 3)
y + 7 = 3x + 9
y = 3x + 2
1. 2 as 4 x 2 is 8 and 4 x 8 is 32 so 32 + 8 = 40
This is quite a complex problem. I wrote out a really nice solution but I can't work out how to put it on the website as the app is very poorly made. Still, I'll just have to type it all in...
Okay so you need to use a technique called logarithmic differentiation. It seems quite unnatural to start with but the result is very impressive.
Let y = (x+8)^(3x)
Take the natural log of both sides:
ln(y) = ln((x+8)^(3x))
By laws of logarithms, this can be rearranged:
ln(y) = 3xln(x+8)
Next, differentiate both sides. By implicit differentiation:
d/dx(ln(y)) = 1/y dy/dx
The right hand side is harder to differentiate. Using the substitution u = 3x and v = ln(x+8):
d/dx(3xln(x+8)) = d/dx(uv)
du/dx = 3
Finding dv/dx is harder, and involves the chain rule. Let a = x+ 8:
v = ln(a)
da/dx = 1
dv/da = 1/a
By chain rule:
dv/dx = dv/da * da/dx = 1/a = 1/(x+8)
Finally, use the product rule:
d/dx(uv) = u * dv/dx + v * du/dx = 3x/(x+8) + 3ln(x+8)
This overall produces the equation:
1/y * dy/dx = 3x/(x+8) + 3ln(x+8)
We want to solve for dy/dx, achievable by multiplying both sides by y:
dy/dx = y(3x/(x+8) + 3ln(x+8))
Since we know y = (x+8)^(3x):
dy/dx = ((x+8)^(3x))(3x/(x+8) + 3ln(x+8))
Neatening this up a bit, we factorise out 3/(x+8):
dy/dx = (3(x+8)^(3x-1))(x + (x+8)ln(x+8))
Well wasn't that a marathon? It's a nightmare typing that in, I hope you can follow all the steps.
I hope this helped you :)
With functions, you take the number that is in the ( ), so we have f(-2), and take the fomula f(x) = 0.8(2 – x) and everywhere you see an 'x' replace it with the -2 f(–2)=0.8(2 – (-2))
We will have to work with the expression of 0.8(2-(-2) When you want to evaluate these types of expressions, you want to use the Order of Operations: Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. First we have to evaluate the parentheses. What is 2-(-2)
its 4.
ok now you got 0.8 (4)
Now we have the remains of 0.8(4). If a number is within the parenthesis, then it means that we have to multiply the number inside with the number that is outside. What is 0.8*4 its 3.2 soooo your answer is going to be
3.2
Answer: 7
Step-by-step explanation:
5+7+9=21
3 total numbers to start with so;
21/3=7
