Which of the following is not an identity?
A. cos^2 x cscx-cscx= -sinx
B. csc^2x + sec^2x = 1
C. sinx(cotx + tanx) = secx
D. cos^2x - sin^2x = 1- 2sin^2x

The Answer is B.

Step-by-step explanation:

I just had this question and the answer came out as B

answer: the price of one pound cabbage = $ 0.8

the point (10,8) represents that the cost of 10 pounds cabbage is $ 8

step-by-step explanation:

since, here is a proportional relation between the number of pounds of cabbage (x) and the price in dollars (y).

therefore, we can write,

⇒ y = k x

where k is the constant of proportionality.

now, point (5,4) is in the line.

thus, it will satisfies the above equation of line.

⇒ 4 = 5 k

⇒ k = 0.8

thus, the equation of the line is,

y = 0.8 x

a) for x = 1,

y = 0.8

therefore, the cost of one pound of cabbage is 0.8 dollars.

b) in the below graph (10,8) represents that the cost of 10 pounds of cabbage is 8 dollars.