Ten !

rewrite with only sin x and cos x.

sin 2x - cos 2x

a- 2 sin2x - 2 sin x cos x + 1
b- 2 sin x
c- 2 sin2x + 2 sin x cos x - 1
d- 2 sin2x - 2 sin x cos x - 1

Option d- 2 sin2x - 2 sin x cos x - 1

Step-by-step explanation:

the trigonometry identities are useful in this case.

Let the identity be:

Sin 2x = 2 sinx cosx

Cos 2x = 2cos²x - 1

Substituting gives:

2 sinx cosx - (2cos²x - 1)

cosx (2sin x - cosx) + 1

solving gives:

2 sin2x - 2 sin x cos x - 1

78.59 is the mean

step-by-step explanation:

arrange the equations with like terms in columns.

analyze the coefficients of x or y.

add the equations and solve for the remaining variable.

substitute the value into either equation and solve.

check the solution.

step-by-step explanation: