Hello
cos ( x + pi/2) =cos(x)cos(pi/2)-sin(x) sin(pi/2)
= cos(x)×0-sin(x) ×1
cos ( x + pi/2) = - sin(x)
Answer:
The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown".
Step-by-step explanation:
In x + 2 = 7, x is a variable, but we can work out its value if we try:)
Answer:
-10
Step-by-step explanation:
Let x = number
10 less than a number is the same number doubled
x-10 = 2x
Subtract x from each side
x-10-x = 2x-x
-10 = x
The number is -10
Area = PI x r^2
area = 3.14 x 6^2
area = 3.14 x 36
area = 113.04 square yards
round the answer if needed.
