The formula for illuminance is given by
E = I / d^2
This formula only holds true for one-dimensional illuminance
The problem asks for the illuminance across the floor. We need to use two variables, x and y.
From Pythagorean Theorem
d^2 = x^2 + y^2
and from Trigonometry
x = d cos t
y = d sin t
The function for the illuminance can be represented by the composite function
E = I cos² t / x²
and
E = I sin² t / y²
The boundary of these functions is:
<span>0 < t < 8
So, the value of t must be in radians and not in degrees</span>
Answer:
Siti's money = RM 430
David = RM 1,290
Farid = RM 280
Step-by-step explanation:
Let
Siti's money = x
David = 3x
Farid = x - 150
Total of their money = RM 2 000
x + 3x + (x - 150) = 2000
4x + x - 150 = 2000
5x = 2000 + 150
5x = 2,150
x = 2,150/5
x = RM 430
Siti's money = x
= RM 430
David = 3x
= 3(430)
= RM 1,290
Farid = x - 150
= 430 - 150
= RM 280
When taking square roots, you can't take square roots of negative roots of negative numbers. So, what will work for the domain of u(x) is what makes u(x) zero or more. We can make an inequality for that.
u(x) ≥ 0.

9x + 27 ≥ 0 by squaring both sides
9x ≥ -27
x ≥ -3
So the domain of the function is when x ≥ -3 is true.
Answer:
21/5
Step-by-step explanation: