Answer:
The most straightforward way to obtain the expression for cos(2x) is by using the "cosine of the sum" formula: cos(x + y) = cosx*cosy - sinx*siny. cos(2x) = cos² (x) - (1 - cos²(x)) = 2cos²(x) - 1. = 2cos²(x) - 1.
Step-by-step explanation:
Answer:
The input have to be -9 to get output 214 with the rule y=-15x+79
Step-by-step explanation:
x is the input, y is the output so:
214 = -15x + 79
214 - 79 = -15x
15x = -135
x = -9
Answer:
w=-4/3, 7/2
Step-by-step explanation:
Answer:
area= 41 cm^2
Step-by-step explanation:
area=5 x 8.2 = 41 cm^2
divide the rhombus in half either way and you have two identical triangles.
area of triangle =0.5 x base x height
double that for the two triangles and you have the area of the rhombus.
Answer:
240 minutes
Step-by-step explanation:
If it's 40 minutes for just 5 papers, we need to figure how many minutes it would take to grade just 1. So you have to divide 40 by 5 which is 8. Then 8 time 30 which is 240.