Answer:
Step-by-step explanation:
The directional derivative of a function in a particular direction u is given as the dot product of the unit vector in the direction of u and the gradient of the function
g(x,y) = sin(π(x−5y)
∇g = [(∂/∂x)î + (∂/∂y)j + (∂/∂z)ķ] [sin(π(x−5y))
(∂/∂x) g = (∂/∂x) sin (πx−5πy) = π [cos(π(x−5y))]
(∂/∂y) g = (∂/∂y) sin (πx−5πy) = - 5π [cos (π(x−5y))]
∇g = π [cos(π(x−5y))] î - 5π [cos (π(x−5y))] j
∇g = π [cos (π(x−5y))] [î - 5j]
So, the question requires a direction vector and a point to fully evaluate this directional derivative now.
 
        
             
        
        
        
ANSWER
D. As the x-values increase, the y-values would decrease
EXPLANATION
The given function is 

The slope of this function is 

Since the slope is negative, there is a negative or an inverse relationship between x and y. 
As the values of x increases, the values of y decreases. 
Also, as the values of x decreases, the values of y increases.
The first option is not true because as x is becoming bigger and bigger negatively, y will become positive.
For instance, when 


This implies that,

Options B is obviously not true because the function has a negative relationship between x and y.
Option C is also false because, x can be positive since it is the independent variable.
See graph
Therefore, the correct answer is option D.
 
        
             
        
        
        
Answer:
B. 39.59
Step-by-step explanation:
So 43 degrees, you know the length of the opposite side (27) and the angle (43 degrees), the only unknown is the hypotenuse. So you're looking for a trigonometric ratio that uses the angle (all of them do, except technically the inverse don't), the opposite side, and the hypotenuse. Sine is defined as 
. So let's plug in known values:

Multiply both sides by x

divide both sides by sin(43)

Normally I would use a calculator, but in this case I'll use the approximation given in the problem of 0.682

simplify the fraction

 
        
             
        
        
        
Answer:
15 kilometers
Step-by-step explanation:
So we know:
For 4 days she runs 1500 meters each day.
For 3 days she runs 3 kilometers each day.
First off, lets convert 1500 meters into kilometers.
There are 1000 meters in a kilometer, so pluggin in 1500 meters:
1500/1000 = 1.5
So for 4 days she runs 1.5 kilometers each day.
Now, to find the total kilometers, we must find multiply the 1.5 kilometers by the 4 days, the 3 kilometers by the 3 days, then add those two together. 
So lets do this:
1.5*4 = 6
So she ran 6 kilometers in the first 4 days.
Next we have:
3*3 = 9
So she ran 9 kilometers in the last 3 days.
Now finally add them together:
6 + 9 = 15
So she ran a total of 15 kilometers.
Hope this helps!
 
        
             
        
        
        
( 2x +5)^2 =4 
2x+5=2
2x=-3
X=-3/2