Jamb 1981 Mathematics Questions
Question 31:
The area of a circular plate is one-sixteenth the surface area of a ball of a ball, If the area of the plate is given as P cm2, then the radius of the ball is
- A \(\frac{2P}{\pi}\)
- B \(\frac{P}{\sqrt{\pi}}\)
- C \(\frac{P}{\sqrt{2\pi}}\)
- D 2\(\frac{P}{\pi}\)
Question 32:
Show that \(\frac{\sin 2x}{1 + \cos x}\) + \(\frac{sin2 x}{1 - cos x}\) is
- A Sin x
- B Cos<sup style='font-size: smaller;'>2</sup>x
- C 2
- D 3
Question 33:
The first term of an Arithmetic progression is 3 and the fifth term is 9. Find the number of terms in the progression if the sum is 81
View Answer & ExplanationQuestion 34:
Simplify T = \(\frac{4R_2}{R_1^{-1} + R_2^{-1} + 4R_3^{-1}}\)
- A \(\frac{4R_1 \times R_2 R_3}{R_2R_3 + R_1R_3 + 4R_1 R_2}\)
- B \(\frac{R_1 R_2 R_3}{R_2R_3 + R_1R_2 + 4R_1 R_2}\)
- C \(\frac{16R_1 R_2 R_3}{R_2R_3 + R_1R_2 + R_1 R_2}\)
- D \(\frac{4R_1 R_2 R_3}{4R_2R_3 + R_1R_2 + 4R_1 R_2}\)
Question 35:
If b = a + cp and r = ab + \(\frac{1}{2}\)cp2, express b2 in terms of a, c, r.
- A B<sup style='font-size: smaller;'>2</sup> = aV + 2cr
- B B<sup style='font-size: smaller;'>2</sup> = ar + 2c<sup style='font-size: smaller;'>2</sup>r
- C B<sup style='font-size: smaller;'>2</sup> = a<sup style='font-size: smaller;'>2</sup> = \(\frac{1}{2}\) cr<sup style='font-size: smaller;'>2</sup>
- D B<sup style='font-size: smaller;'>2</sup> = \(\frac{1}{2}\)ar<sup style='font-size: smaller;'>2</sup> + c
- E B<sup style='font-size: smaller;'>2</sup> = 2cr - a<sup style='font-size: smaller;'>2</sup>