Answer
100 pizzas
Step-by-step explanation:
sin x = cos 54 = sin (90-54) = sin 46
Hence x = 46 deg
Same technique. Sin 21 = cos (5x+9) = sin (90-5x-9)
81-5x = 21
Or 5x = 60
Or x = 12 deg
hope it helps
We can use ratios, in other words, if one part of the photo is changed x times, how many times does the other part change?
We can set up the proportion as :
width 1 : length 1 = width 2 : length 2
20 : 30 = 5 : x
We do inverse multiplication, or multiply the outer with outer and inner with inner (W1 * L2 and L1 * W2)
20*x = 30*5
20x = 150
Divide all by 10
2x = 15
Divide all by 2 to isolate x
x = 15/2
x = 7.5cm
LHS: =

(using

)
We know

so we can replace the sin²x in the LHS expression as follows

which is the RHS.
It’s D, because the x-value, 8, has two y-values, the 5 and 9. In order to be a function, each x-value has to have only one y-value.