I'm not sure how the other forum solved it, but here is another way to approach the problem.
If you look at the slope of a line and realize that because we're told the two lines are 90 degrees from each other, you know the lines are perpendicular.
so what ist he slope of a line? \(y = \frac{1}{3}x + 0\) Sure we don't need the + 0, but it helps to see all the parts there.
Now I used 1/3, but that's just a number to show the formula for a line.
If the coordinates we do know were used to determine the slope of the line, what would the equation look like?
\(y = -\frac{1}{\sqrt{3}}x + 0\)
It's a negative because the slope runs from top left to bottom right and those lines are always negative. So if we know the slope, then how would we figure what the slope is of the perpendicular line, with point {s,t}?
Invert and negate the slope. We can use the same exact numbrs because we know the line is the radius of a circle and therefore the same length. By using the same numbers, we know that it will be the same length and be the correct values for {s,t}
so inverted the slope becomes \(\frac{\sqrt{3}}{1}x\)
Now if before we had \(sqrt{3}\) on bottom, and it was the x value, and now it is on top, it will not be the x value, but the y value, which corresponds to \(t\).
Hope this helps present a different way of looking at it. Answering the question won't take nearly as long as exlaining it.
uzonwagba wrote:
In the figure above, P and O lie on the circle with center O. What is the value of s?
A) 1/2
B) 1
C) sqrt(2)
D) sqrt(3)
E) sqrt(2)/2
It comes from GMATPrep. Thanks!