Reciprocals Questions and Answers - Form 2 Topical Mathematics

QUESTIONS                                                                        

1. Use the reciprocal table to evaluate giving your answer to three significant figures.
   ¹⁰/ _0.834 − ³/_129.64
2. Find the reciprocals of the numbers 807 and 0.0591; Hence evaluate
   ⁵/₈₀₇ + ⁴/_0.0591 
3. Use reciprocal tables to find the value of:
   
   
4. Find without using a calculator, the value of:
   
   
5. Use tables of cubes, cube roots and reciprocal to find the value of:-
   
   
6. Determine the value of a for which
   ¹/₁₂₇ + ¹/_11.5 = ¹/_a
   Use mathematical tables only
7. Use tables of squares, square roots and reciprocals only to find the value of x correct to 4 significant figures:
   
8. Use reciprocal tables to find the value of
   
9. Use tables of reciprocals only to work out;
   ³/_0.6735 + ¹³/_0.156
10. Using tables of squares, cube roots and reciprocals find the value of x.
    ¹/_x = ¹/_{0.00259^¹/³} − ¹/_1.28^² 
11. Use reciprocal, square and square root tables to evaluate, to 4 significant figures, the expression
    

ANSWERS

1. ¹⁰/_0.834  − ³/_129.64 
   (10 x 1.199) − (3 x 0.007713)
   11.99 − 0.923139
   11.966861
   12.0
2. 807 → 0.001239
   0.0591 → 16.92
   5(0.001239) + 4(16.92)
   = 67.69
3. ^¹/_³ {2 x 1.5065 + 5 x 1.2004}
   ^¹/_³ (3.013 + 6.002) (0.3333)
   = 9.015 x 0.3333
   = 3.005 (3 dp)
4.  
   
5. ⁴/_(8.68)^³ + ⁵/_34.46 
   ⁴/_653.97 + (0.1451)^¹/_³
   4(0.1529) + 0.5255
   0.6116 + 0.5255 = 1.1371
6. ¹/_a = 0.007874 + 0.0869
   = 0.9483
   a = 10.55
7. 
   
   √3.87946 = √3.879
   = 1.9695
   = 1.970(4s.f)
8. 
   
9. 3x1.485 + 13x6.410
   = 4.455 + 83.33
   = 87.785
   
   ALT
   ³⁰/_6.735 + ¹³⁰/_1.56 = 30 x 0.1485 + 130x0.641
   = 4.455 + 83.33
   = 87.785