To solve this problem you must apply the proccedure shown below:
1. If the function
is shifted
units left, this means that you must substitute the value of
by
to find
, as following:

2. Now, expand the function:

3. Then, you have that
is:

Therefore, the answer is: 
Answer:
I. AC = 15 cm
II. h = 7.4 cm
Step-by-step explanation:
I. Determination of AC
AB = 9 cm
BC = 12 cm
AC =?
The length AC can be obtained by using pythagoras theory as illustrated below:
AC² = AB² + BC²
AC² = 9² + 12²
AC² = 81 + 144
AC² = 225
Take the square root of both side
AC = √225
AC = 15 cm
II. Determination of the height.
AB = 9 cm
AD = 5.1 cm
BD = h =?
The height of the triangle can be obtained by using pythagoras theory as illustrated below:
AB² = AD² + BD²
9² = 5.1² + h²
81 = 26.01 + h²
Collect like terms
h² = 81 – 26.01
h² = 54.99
Take the square root of
h = √54.99
h = 7.4 cm
If this is what you meant...
Using formula sin^2 x +cos^2 x = 1 you get 1 - cos^2(9x) = sin^2(9x)
so in this way this fraction will be rewrited
sin9x/(1-cos^2(9x) = sin9x / sin^2(9x) = 1/sin9x