Hi Dhwani
1. A line which lines makes intercept a and b at X-axis and Y-axis respectively has an equation: x/a + y/b = 1
According to given condition, we have a + b = 1 and ab = -6 clearly (a, b) ≡ (3, -2) or (-2, 3). So the two lines are x/3 - y/2 = 1 => **2x - 3y - 6 = 0** AND -x/2 + y/3 = 1 => **3x - 2y + 6 = 0**.
4. y = 2x² - mx + 3 represents an upward parabola. It will cut X-axis in two distinct points if discriminant of the quadratic expression is > 0.
That is, m² - 4(2)(3) > 0
=> m² > 24 i.e. m > 2√6.
All questions are based on basic co-ordinate for which I'd recommend you to go through any 11-12th std text book.
Kamal Lohia |