2cos^2 x + 3sin x = 0
2(1 - sin^2 x) + 3sin x = 0
2 - 2sin^2 x + 3sin x = 0
2sin^2 x - 3sin x - 2 = 0
Let sin x = m, then
2m^2 - 3m - 2 = 0
2m^2 + m - 4m - 2 = 0
m(2m + 1) - 2(2m + 1) = 0
(m - 2)(2m + 1) = 0
m = 2 or m = -1/2
Now, sin x = -1/2
Therefore, x = 1/6(12nπ - π) and 1/6(12nπ + 7π)
Answer:
24
Step-by-step explanation:
you would multiply 3 tables by 4 students, that would be twelve. then 12 times 2, which is 24. Or you could find the pencils by multiplying 2 with 8 and then multiplying by 3. :)
Answer:
Total number of tables of first type = 23.
Total number of tables of second type = 7
Step-by-step explanation:
It is given that there are 30 tables in total and there are two types of tables.
Let's call the two seat tables, the first type as x and the second type as y.
∴ x + y = 30 ......(1)
Also a total number of 81 people are seated. Therefore, 2x number of people would be seated on the the first type and 5y on the second type. Hence the equation becomes:
2x + 5y = 81 .....(2)
To solve (1) & (2) Multiply (1) by 2 and subtract, we get:
y = 7
Substituting y = 7 in (1), we get x = 23.
∴ The number of tables of first kind = 23
The number of tables of second kind = 7