Solve for x to four significant digits 7^2x-1=316

Temperature rose 9°f in 3 hours if the starting wad -5°f what was the final temperature

svetlana [45]

4F is the final temp.

3 0

3 years ago

A roller coaster makes an angle of 52 degrees with the ground. The horizontal distance from the crest of the hill to the bottom

Ann [662]

Answer:

Step-by-step explanation:

Using soh cah toa

Sin=opp/hot

Sin 52°=h/121

h=sin52°×121

h=0.7880×121feet

h=95.348feet

4 0

4 years ago

Hey loves!!! Can any of you lovely people give me a hand?

posledela

Hey There!!

Your best answer will be A.

Step-by-step explanation:

Because, The SAS stands for Side Angle Side if you need two sides and then the angle needs to be between them.

The first one works because the angle is in-between the 2 sides. The second one really doesn't work very well. Because, It actually have 2 angles and it only need one. Well, The third one it doesn't work because the angle isn't between from both sides. The fourth one doesn't work at all they are only sides and no angles. Hope This helps <3!!

6 0

4 years ago

Evaluate the integral by making an appropriate change of variables.

VARVARA [1.3K]

By inspecting the integrand, the "obvious" choice for substitution would be

u = y + x

v = y - x

Solving for x and y, we would have

x = (u - v)/2

y = (u + v)/2

in which case the Jacobian and its determinant are

$J=\begin{bmatrix}x_u&x_v\\y_u&y_v\end{bmatrix}=\dfrac12\begin{bmatrix}1&-1\\1&1\end{bmatrix}\implies|\det J|=\left|\dfrac12\right|=\dfrac12$

The trapezoid R has two of its edges on the lines x + y = 8 and x + y = 9, so right away, we have 8 ≤ u ≤ 9.

Then for v, we observe that when x = 0 (the lowest edge of R), v = y ; similarly, when y = 0 (the leftmost edge of R), v = -x. So

-x ≤ v ≤ y

-(u - v)/2 ≤ v ≤ (u + v)/2

-u + v ≤ 2v ≤ u + v

-u ≤ v ≤ u

So, the integral becomes

$\displaystyle\iint_R5\cos\left(7\frac{y-x}{y+x}\right)\,\mathrm dA=\int_8^9\int_{-u}^u\frac52\cos\left(\frac{7v}u\right)\,\mathrm dv\,\mathrm du$

$=\displaystyle\frac52\int_8^9\frac u7(\sin7-\sin(-7))\,\mathrm du$

$=\displaystyle\frac57\sin7\int_8^9u\,\mathrm du$

$=\displaystyle\frac5{14}\sin7(9^2-8^2)=\boxed{\frac{85}{14}\sin7}$

4 0

3 years ago

A jar contains 16 quarters, 6 dimes ,7 nickels and 11 pennies, if one coin is selected at random, what is the probability it is

maksim [4K]

Answer:

11/20

Step-by-step explanation:

5 cents is worth $0.05.

A quarter is worth $0.25.

A dime is worth $0.10

A nickel is worth $0.05

A penny is worth $0.01

In total there are 40 coins in the jar.

The coins that are worth more than $0.05 dollars are the dimes and quarters, so there are 22 coins worth more than $0.05.

Therefore, the probability of of picking a coin worth more than 5 cents is:

22 / 40 = 11/20

5 0

3 years ago