Saved Bookmarks
| 1. |
in the given figure `y=x^(2)+bx+c` is a quadratic polynomial which meets x-axis at A and B and y-axis at C Q is vertex of quadratic polynomial and foot of perpendicular from Q to x-axis and y-axis are P and R respectively. Then answer the following questions. Q. If `("area of" DeltaABC)/("Area of rectangle" OPQR)=(8)/(3)` satisfies the relation `b^(2)=kc` then `k` will beA. `9`B. `(2)/(9)`C. `(9)/(2)`D. `2` |
|
Answer» Correct Answer - B `((1)/(2)(beta-alpha)c)/(((b^(2)-4c)/(4))(-(b)/(2)))=(8)/(3)` squaring and using `(beta-alpha)^(2)=b^(2)-4c` `9c^(2)=4b^(4)-16b^(2)c` `4b^(4)-16b^(2)c-9c^(2)=0` `4b^(4)-18b^(2)c+2b^(2)c-9c^(2)=0` `(2b^(2)+c)(2b^(2)-9c)=0impliescgt0because2b^(2)+cne0` `(b^(2))/(c)=(9)/(2)implies(b^(2))/(c)=4.5` |
|