<u>Answer:</u>
The basic identity used is
.
<u>Solution:
</u>
In this problem some of the basic trigonometric identities are used to prove the given expression.
Let’s first take the LHS:

Step one:
The sum of squares of Sine and Cosine is 1 which is:

On substituting the above identity in the given expression, we get,
Step two:
The reciprocal of cosine is secant which is:

On substituting the above identity in equation (1), we get,

Thus, RHS is obtained.
Using the identity
, the given expression is verified.
Answer:

Step-by-step explanation:
According to the trigonometric ratios in aright triangle :

Given: ΔBCA ~ ΔSTR
Since , corresponding angles of two similar triangles are equal.
So, ∠C = ∠T ...(i) [Middle letter]
In triangle STR
...(ii)
From (i) and (ii), we have

The next step is to solve the recurrence, but let's back up a bit. You should have found that the ODE in terms of the power series expansion for


which indeed gives the recurrence you found,

but in order to get anywhere with this, you need at least three initial conditions. The constant term tells you that

, and substituting this into the recurrence, you find that

for all

.
Next, the linear term tells you that

, or

.
Now, if

is the first term in the sequence, then by the recurrence you have



and so on, such that

for all

.
Finally, the quadratic term gives

, or

. Then by the recurrence,




and so on, such that

for all

.
Now, the solution was proposed to be

so the general solution would be


let the numbers be x and y
x + y = 1600 ----*
12%x = 20%y
0.12x = 0.2y
y = <u>0</u><u>.</u><u>1</u><u>2</u><u>x</u>
0.2
y = 0.6x
substitute in * eqn
x + 0.6x = 1600
1.6x = 1600
x = 1000
then,
y = 0.6*1000
y = 600
the numbers are 1000 and 600
The least common multiple of 96, 144, and 224 is 2016.
Hope this helps! :D