QR Questions

[sam26880]

Advertisement - Members don't see this ad

Ok..couple of questions

(1) I forgot which trig functions are positive in a specific quadrant. Can someone explain that?

(2) Here's a topscore question about finding a shaded area. You're given a square inscribed in a circle of radius 4. You need to find the shaded area.
I understand everything in the explanation but I don't understand why they divide the area of the square by 2.

By the way the answer is 16pi - 32. Can someone explain this.

(3) One of the questions had to do with converting gallons to ounces and quarts. What other conversion factors should we memorize for the DAT?

Thanks for all your help.

 

[Streetwolf]

Ok..couple of questions

(1) I forgot which trig functions are positive in a specific quadrant. Can someone explain that?

(2) Here's a topscore question about finding a shaded area. You're given a square inscribed in a circle of radius 4. You need to find the shaded area.
I understand everything in the explanation but I don't understand why they divide the area of the square by 2.

By the way the answer is 16pi - 32. Can someone explain this.

(3) One of the questions had to do with converting gallons to ounces and quarts. What other conversion factors should we memorize for the DAT?

Thanks for all your help.

(1) Just consider what the functions are. Remember that cosine corresponds to x and sine corresponds to y. So when you are in a quadrant with y > 0, the sine value will be positive. And so forth. Since tangent is sine/cosine, it depends on both values. If you are in the 4th quadrant (x > 0, y < 0) then cosine is positive (x > 0) and sine is negative (y < 0). Then tangent is negative (pos/neg = neg).

(2) The area of the circle is 16pi, you seem to have no problems with that. Then you need to subtract the area of the square. You have the radius of the circle = 4. That means the diameter is 8. So the diagonal of the square is 8. If the diagonal of the square is 8, then the side length is 4sqrt(2) (why? Think pythagorean...). So s^2 = 32. The answer is 16pi - 32.

(3) Just the basics. Anything with meters. Know inches, feet, yards, inches to cm, etc. Cups, fl ounces, pints, gallons, quarts. I doubt they'd ask about tablespoons or teaspoons.