There's a key problem in this question compelling you to actually rewrite it like that! Mathematically that is inaccurate and incorrect. If you do 72(8+19) it seems as if you are going to do 8+19*72 as in algebra whatever is outside the bracket is bound to go multiplied so technically (8+19)+72 would make more sense and the answer is
Using bidmas do the brackets first
8+19= 27
27+72=99
AB = 6 cm, AC = 12 cm, CD = ?
In triangle ABC, ∠CBA = 90°, therefore in triangle BCD ∠CBD = 90° also.
Since ∠BDC = 55°, ∠CBD = 90°, and there are 180 degrees in a triangle, we know ∠DCB = 180 - 55 - 90 = 35°
In order to find ∠BCA, use the law of sines:
sin(∠BCA)/BA = sin(∠CBA)/CA
sin(∠BCA)/6 cm = sin(90)/12 cm
sin(∠BCA) = 6*(1)/12 = 0.5
∠BCA = arcsin(0.5) = 30° or 150°
We know the sum of all angles in a triangle must be 180°, so we choose the value 30° for ∠BCA
Now add ∠BCA (30°) to ∠DCB = 35° to find ∠DCA.
∠DCA = 30 + 35 = 65°
Since triangle DCA has 180°, we know ∠CAD = 180 - ∠DCA - ∠ADC = 180 - 65 - 55 = 60°
In triangle DCA we now have all three angles and one side, so we can use the law of sines to find the length of DC.
12cm/sin(∠ADC) = DC/sin(∠DCA)
12cm/sin(55°) = DC/sin(60°)
DC = 12cm*sin(60°)/sin(55°)
DC = 12.686 cm
The answer is 96. just multiply 6 *2 =12*2=24*2=48*2=96
Answer:
<em>Correct answer:</em>
<em>A. I and II</em>
<em></em>
Step-by-step explanation:
First of all, let us have a look at the steps of finding inverse of a function.
1. Replace y with x and x with y.
2. Solve for y.
3. Replace y with 
Given that:
Now, let us find inverse of each option one by one.
I. y = x, a(x) = x
Replacing y with and x with y:
x = y
x = 
= 
Hence, I is true.
II. 
Replacing y with and x with y:
= Hence, II is true.
III. 
Replacing y with and x with y:
Hence, III is not true.
IV. 
Replacing y with and x with y:
![x =y^{3}\\\Rightarrow y = \sqrt[3] x\\\Rightarrow a^{-1}(x) = \sqrt[3]{x} \ne a(x)](https://tex.z-dn.net/?f=x%20%3Dy%5E%7B3%7D%5C%5C%5CRightarrow%20y%20%3D%20%5Csqrt%5B3%5D%20x%5C%5C%5CRightarrow%20a%5E%7B-1%7D%28x%29%20%3D%20%5Csqrt%5B3%5D%7Bx%7D%20%5Cne%20a%28x%29)
Hence, IV is not true.
<em>Correct answer:</em>
<em>A. I and II</em>
<em></em>
