Answer:
1. 0, 2 π , π , 2 π/3 , 4 π/3
2. 7 π/6 , 11 π/6
Step-by-step explanation:
1. we want to find the value of theta
Let us represent theta by x for ease of documentation
So we have ;
sin 2x + sin x = 0
Mathematically;
sin 2x = 2sinxcosx
So;
2 sin x cos x + sin x = 0
sin x (2 cos x + 1) = 0
sin x = 0
or
2cos x + 1 = 0
x = arc sin (0)
within the given range;
x = theta = 0 , 2 π , π
For;
2 cos x + 1 = 0
2cos x = -1
cos x = -1/2
cos x = -0.5
x = arc cos (-0.5)
x = 2 π/3 , 4 π/3
2. cos 2 x = 1 + sin x
Mathematically;
cos 2 x = 1-2 sin^2x
let sin x = y
1-2y^2 = 1 + y
y = -2y^2
1 = -2y
y = -1/2
y = -0.5
sin x = y
sin x = -0.5
x = arc sin (-0.5)
x = 7 π/6 , 11 π/6
Answer:
The number of ways to select 2 cards from 52 cards without replacement is 1326.
The number of ways to select 2 cards from 52 cards in case the order is important is 2652.
Step-by-step explanation:
Combinations is a mathematical procedure to compute the number of ways in which <em>k</em> items can be selected from <em>n</em> different items without replacement and irrespective of the order.

Permutation is a mathematical procedure to determine the number of arrangements of <em>k</em> items from <em>n</em> different items respective of the order of arrangement.

In this case we need to select two different cards from a pack of 52 cards.
- Two cards are selected without replacement:
Compute the number of ways to select 2 cards from 52 cards without replacement as follows:



Thus, the number of ways to select 2 cards from 52 cards without replacement is 1326.
- Two cards are selected and the order matters.
Compute the number of ways to select 2 cards from 52 cards in case the order is important as follows:




Thus, the number of ways to select 2 cards from 52 cards in case the order is important is 2652.
Answer:
8
Step-by-step explanation:
3 + 4 = 7
6/12 + 1/2 = 1
7+1 = 8