Given the equation:
cos²(x) + 9cos(x) = 5cos(x) + 5
cos²(x) + 9cos(x) - 5 cos(x) - 5 = 0
cos²(x) + 4cos(x) - 5 = 0
[cos(x) + 5][cos(x) - 1] = 0
cos (x) = - 5 x ∉ ℝ; so:
cos (x) = 1
Then;
x = 0, and x = 2π
Answer:
D. -12s squared + 11st - 2t squared
Step-by-step explanation:
FOIL:
-3s(4s) - 3s(-t) + 2t(4s) + 2t(-t)
- 12s² + 3st + 8st - 2t²
Simplify.
- 12s² + 11st - 2t²
You can use the greatest common factor to simplify fractions.
A ratio is an expression that tells us the quotient of two numbers.
Answer:
Item or service cost times sales tax so $45x0.6= meal and then you add 20% of 27
Extraneous solutions, is answers that we get because of squaring both sides of the radical equation, but in reality, they are not going to be the solutions of the given equation.
(√(4x+41))²=(x+5)²
4x+41=x²+10x+25
x²+6x-16=0
(x-2)(x+8)=0
x1=2 , x2=-8,
And now we must to check them by substitution into initial equation
√(4x+41)=x+5
1) x=2, √(4*2+41)=2+5, √49=7, 7=7 true
2) x=-8, √(4*(-8)+41)=-8+5, √9 =-3 false,
so an extraneous solution x=-8