3x-13=2
move -13 to the other side
sign changes from -13 to +13
3x-13+13=2+13
3x=2+13
3x=15
divide both sides by 3 to get x by itself
3x/3=15/3
cross out 3 and 3, divide by 3 and then becomes 1*1*x=x
x=15/3
x=5
answer:
x=5
Answer: 0.5714
Step-by-step explanation:
Answer:
The 90% confidence interval estimate of the mean annual income of all company presidents is ($579,545, $590,580).
Step-by-step explanation:
The information provided is:
The critical value of <em>z</em> for 90% confidence level is, 1.645.
Compute the 90% confidence interval estimate of the mean annual income of all company presidents as follows:
Thus, the 90% confidence interval estimate of the mean annual income of all company presidents is ($579,545, $590,580).
This interval implies that there is 90% probability that the true mean annual income of all company presidents is within this interval.
For cos(2x) * (2cos(x) + 1) = 0, use the double angle identity for cos(2x), which is cos^2 x - sin^2 x = cos^2 x - (1-cos^2) = 2cos^2 x - 1.
So we have (2cos^2 x - 1)(2cos x + 1) = 0. So 2cos^2 x -1 = 0 or x = 0 and 2pi.
For 2sec^2 x + tan^2 x - 3 = 0, use the identity sec^2 x = tan^2 x + 1, so we have
2(tan^2 x + 1) + tan^2 x - 3 = 0 or
<span>2tan^2 x + tan^2 x - 1 = 0 or
</span>3 tan^2 x = 1.
So x = pi/2, pi/2 + pi = 3pi/2.