Answer:
A
Step-by-step explanation:
So we have the piecewise function:

And we want to find f(8).
Since our input value is 8, choose the equation that fits our input.
The first equation demand x to be less than 3. 8 is not less than 3, so we won't use that.
The second equation demand x to e greater than or equal to 3 and less than 8. 8 is <em>not</em> less than 8. So, we won't use that.
The third equation demands x to be greater than or equal to 8. 8 is greater than or equal to 8, so we'll use the third equation.
So:


There're nothing more to do, we're done :)
The answer is A.
Edit: Improved Format
Answer:
But what do we have to do ? like add subtract or multiply? i dont know
Step-by-step explanation:
A polar coordinate is that which can be written as (r, θ) where r is the radius and θ is the angle.
The radius, r, is also the hypotenuse of the right triangle that can be formed. Hence, it can be calculated through the equation,
r² = x² + y²
If we are to simplify this for the r alone, we have,
r = sqrt (x² + y²)
Substituting the known values,
r = sqrt ((4)² + (-4)²) = 4√2
The x and y can be related through the trigonometric function, tangent.
tan θ = y/x
To solve for θ
θ = tan⁻¹(y/x) = tan⁻¹(-4/4) = -45° = 315°
Hence, the polar coordinate is <em>(4√2, 315°)</em>