Answer: X = 44.4 degrees
Step-by-step explanation: The figure given is a right angled triangle with two sides given as well as one angle unknown.
Angle X, which is the unknown, is the reference angle in this question. So we have an opposite which is the side facing the reference angle (line 7 units) and we have an hypotenuse which is the side facing the right angle (line 10). Having an opposite and an hypotenuse, we can use the trigonometric ratio of sine.
SinX = opposite/hypotenuse
SinX = 7/10
SinX = 0.7000
Looking up a table of values or checking the calculator, 0.7000 under sine of angles gives 44.4270
Therefore angle X is approximately 44.4 degrees (approximated to the nearest tenth)
Answer:
1 solution
Step-by-step explanation:
The lines intersect 1 time
Answer:
Yes, it is invertible
Step-by-step explanation:
We need to find in the matrix determinant is different from zero, since iif it is, that the matrix is invertible.
Let's use co-factor expansion to find the determinant of this 4x4 matrix, using the column that has more zeroes in it as the co-factor, so we reduce the number of determinant calculations for the obtained sub-matrices.We pick the first column for that since it has three zeros!
Then the determinant of this matrix becomes:
![4\,*Det\left[\begin{array}{ccc}1&4&6\\0&3&8\\0&0&1\end{array}\right] +0+0+0](https://tex.z-dn.net/?f=4%5C%2C%2ADet%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%264%266%5C%5C0%263%268%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%2B0%2B0%2B0)
And the determinant of these 3x3 matrix is very simple because most of the cross multiplications render zero:
![Det\left[\begin{array}{ccc}1&4&6\\0&3&8\\0&0&1\end{array}\right] =1 \,(3\,*\,1-0)+4\,(0-0)+6\,(0-0)=3](https://tex.z-dn.net/?f=Det%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%264%266%5C%5C0%263%268%5C%5C0%260%261%5Cend%7Barray%7D%5Cright%5D%20%3D1%20%5C%2C%283%5C%2C%2A%5C%2C1-0%29%2B4%5C%2C%280-0%29%2B6%5C%2C%280-0%29%3D3)
Therefore, the Det of the initial matrix is : 4 * 3 = 12
and then the matrix is invertible
Answer: -3x + 15
Step-by-step explanation: you multiply -3 by x so you get -3x, then you multiply -3 by -5 and get +15, then you just put the two together in an equation.