Answer: 5.
- A 1
- B 2
- C 3
- D 5
Correct answer: D. 5
Explanation: Three equations: a+b+c=1, 4a+2b+c=1, 9a+3b+c=5. From first two: 3a+b=0. From last two: 5a+b=4. So 2a=4, a=2, b=-6. c=1-2+6=5. f(0)=c=5.
A complex number z = a+ib is plotted as a point (or vector from the origin) on the Argand plane, with the real part along the horizontal axis and the imaginary part along the vertical; its modulus |z| is the vector's length, and its argument θ is the angle from the positive real axis.
Concept context
Complex numbers in a+ib form, modulus, argument, polar form, cube roots of unity, and quadratic equations with complex roots
Read the full Complex Numbers and Quadratic Equations notes →