show that the polynomial x2-2x+5 has no real zero.

Asked by chandra.abhijit | 24th Jun, 2015, 10:53: PM

Expert Answer:

C o n s i d e r space t h e space g i v e n space p o l y n o m i a l space x squared minus 2 x plus 5. H e r e comma space a equals 1 comma space b equals negative 2 space a n d space c equals 5 therefore D i s c r i m i n a n t space D equals open parentheses negative 2 close parentheses squared minus 4 cross times 1 cross times 5 equals 4 minus 20 equals negative 15 S i n c e space t h e space v a l u e space o f space d i s c r i m i n a n t comma space minus 15 less than 0 comma space t h e space g i v e n space p o l y n o m i a l space h a s space n o space r e a l space z e r o s.

Answered by Vimala Ramamurthy | 25th Jun, 2015, 08:41: AM