If sinx=45, find 1+cot2xcsc2x−1.
132
259
313
411
Correct answer is B
sinx=oppHyp=45
52 = 42 + adj2
adj2 = 25 - 16 = 9
adj = √9 = 3
tanx=43
cotx=143=34
cot2x=(34)2=916
cscx=1sinx
= 145=54
csc2x=(54)2=2516
∴1+cot2xcsc2x−1=1+9162516−1
= 2516÷916
= 259
In the circle above, with centre O and radius 7 cm. Find the length of the arc AB, when < AOB = 57°
5.32 cm
4.39 cm
7.33 cm
6.97 cm
Correct answer is D
Length of arc = \frac{\theta}{360°} \times 2 \pi r
= \frac{57}{360} \times 2 \times \frac{22}{7} \times 7
= 6.97 cm
Marks | 1 | 2 | 3 | 4 | 5 |
Frequency | 2y - 2 | y - 1 | 3y - 4 | 3 - y | 6 - 2y |
The table above is the distribution of data with mean equals to 3. Find the value of y.
5
2
3
6
Correct answer is B
Marks (x) | 1 | 2 | 3 | 4 | 5 | |
Frequency (f) | 2y - 2 | y - 1 | 3y - 4 | 3 - y | 6 - 2y | 3y + 2 |
fx | 2y - 2 | 2y - 2 | 9y - 12 | 12 - 4y | 30 - 10y | 26 - y |
Mean = \frac{\sum fx}{\sum f}
3 = \frac{26 - y}{3y + 2}
3(3y + 2) = 26 - y
9y + 6 = 26 - y
9y + y = 26 - 6
10y = 20 \implies y = 2