Easy -1.2 This is a straightforward application of the discriminant formula b²-4ac with simple arithmetic (25-24=1), followed by direct recall that positive discriminant means two distinct real roots. It requires only basic formula recall and no problem-solving, making it easier than average for A-level.
substituted but discriminant part must be correct;
clearly found as discriminant, or stated as b2 −4ac, not
just seen in formula eg M1A0 for b2 −4ac = 1=1;
condone discriminant not used; ignore incorrect roots
found
Question 2:
2 | b2 −4ac soi
1 www
2 [distinct real roots] | M1
A1
B1 | or B2
B0 for finding the roots but not saying
how many there are | allow seen in formula; need not have numbers
substituted but discriminant part must be correct;
clearly found as discriminant, or stated as b2 −4ac, not
just seen in formula eg M1A0 for b2 −4ac = 1=1;
condone discriminant not used; ignore incorrect roots
found
Find the discriminant of $3x^2 + 5x + 2$. Hence state the number of distinct real roots of the equation $3x^2 + 5x + 2 = 0$. [3]
\hfill \mbox{\textit{OCR MEI C1 Q2 [3]}}