in the xy plane, point (x,y) lies on the circle with equation x^2+y^2=1 and on the line with the equation y=2x what is the value of xy?
It sat math subject test level 1
Thanks in advance 🙂

if (4/3)y = (3/4)x , for what value of x will x = y?

Hello Mike,
Basically, I’m having a little trouble understanding the explanation for #3 on the Working in Three Dimensions section on page 284. I got a little lost after the part where you explained how d was the height (this makes sense to me). Like, how do we “recognize that the ab term in the surface area expression must represent both the top and the bottom of the prism”? I think it’s somewhere from the equation but I don’t know where. I would greatly appreciate your help here Mike. Thanks!

Hello! For question #8 on page 111 in the Exponents and Exponential Functions section, where did the 2^2 come from? The answer was 82.41*2^2= 329.6. Thank you ^_^.

Hi! For question #9 on page 111 in the Exponents and Exponential Functions section, how did you get 2mn in m^2+2mn+n^2=m^2+n^2? Thank you!

If the graphs of y=f ^-1(x) and y=f(x) are identical then each of these graphs must be symmetrical about the

A)y-axis B)X-axis c)origin d)line y=-x e)line y=x

In the figure above ac is a diameter of a circle with center 0 if ab =3 and bc=5 then the area of the semicircle abc is ?

Hi – I have the fourth edition (2016). Is this the latest edition? Do you have any updates available online? Thanks!

Hello Mike,
For problem 2 on page 284 (relating to “Working in Three Dimensions”), I had difficulty answering the question, because I don’t know what the inner radius of a sphere and how that differs from the outer radius of a sphere. Since I’m not able to find anything on the Internet that talks about this, could you please explain the difference to me?
And could you then tie it back to how the entire inner/outer radius thing is relevant to the question at hand (#2 on page 284)?