Finding Intercepts

Some useful deductions about roots of a polynomial equation and their nature are:

• A polynomial equation of order n can have a maximum of n roots, real or imaginary.
  
• Imaginary roots occur in pairs like 1+3i and 1-3i.
  
• Roots having square root terms occur in pairs like 1+?3 and 1-?3.
  
• If a polynomial equation involves only even powers of x and all terms are positive, then all roots of polynomial equation are imaginary (complex). For example, roots of the quadratic equation x⁴ + 2x² + 4 = 0 are complex.