Answer:
-1
Step-by-step explanation:
first 5+3=8
8-9=-1
First we'll do two basic steps. Step 1 is to subtract 18 from both sides. After that, divide both sides by 2 to get x^2 all by itself. Let's do those two steps now
2x^2+18 = 10
2x^2+18-18 = 10-18 <<--- step 1
2x^2 = -8
(2x^2)/2 = -8/2 <<--- step 2
x^2 = -4
At this point, it should be fairly clear there are no solutions. How can we tell? By remembering that x^2 is never negative as long as x is real.
Using the rule that negative times negative is a positive value, it is impossible to square a real numbered value and get a negative result.
For example
2^2 = 2*2 = 4
8^2 = 8*8 = 64
(-10)^2 = (-10)*(-10) = 100
(-14)^2 = (-14)*(-14) = 196
No matter what value we pick, the result is positive. The only exception is that 0^2 = 0 is neither positive nor negative.
So x^2 = -4 has no real solutions. Taking the square root of both sides leads to
x^2 = -4
sqrt(x^2) = sqrt(-4)
|x| = sqrt(4)*sqrt(-1)
|x| = 2*i
x = 2i or x = -2i
which are complex non-real values
Answer:
cos4B =1-8sin^2(B)+8sin^4(B)
Step-by-step explanation:
cos4B =1-8sin^2(B)+8sin^4(B)
Answer:
87.5%
Step-by-step explanation:
1) divide 7 by 8 which gives you 0.875
2) move the decimal in 0.875 two spaces to the right which makes it as a percent of 87.5%
(1) the diameter is 20 inches whats the radius? And whats the circumference?
Radius is half the diameter, Answer: 10 inches
Circumference is pi times the radius, Answer: 10π inches
I won't bother with the approximation, though this one is easy, 31.4159 inches. I'll leave the rest of the calculator work to you if necessary.
(2) the diameter 11 inches whats the radius? And whats the circumference?
Radius half, Answer: 5.5 inches. Circ: 5.5π inches
(3) the diameter 3.5 inches whats the radius? And whats the circumference?
Radius, 1.75 inches. Circ: 1.75π inches
