Use Pythagorean thrm
17^2+10^2=21^2
289+100=441
389≠441
This is not a right triangle
Step-by-step explanation:
(cos 10° − sin 10°) / (cos 10° + sin 10°)
Rewrite 10° as 45° − 35°.
(cos(45° − 35°) − sin(45° − 35°)) / (cos(45° − 35°) + sin(45° − 35°))
Use angle difference formulas.
(cos 45° cos 35° + sin 45° sin 35° − sin 45° cos 35° + cos 45° sin 35°) / (cos 45° cos 35° + sin 45° sin 35° + sin 45° cos 35° − cos 45° sin 35°)
sin 45° = cos 45°, so dividing:
(cos 35° + sin 35° − cos 35° + sin 35°) / (cos 35° + sin 35° + cos 35° − sin 35°)
Combining like terms:
(2 sin 35°) / (2 cos 35°)
Dividing:
tan 35°
To take out terms outside the radical we need to divide the power of the term by the index of the radical; the quotient will be the power of the term outside the radical, and the remainder will be the power of the term inside the radical.
First, lets factor 8:
Now we can divide the power of the term, 3, by the index of the radical 2:

= 1 with a remainder of 1
Next, lets do the same for our second term

:

= 3 with a remainder of 1
Again, lets do the same for our third term

:

with no remainder, so this term will come out completely.
Finally, lets take our terms out of the radical:

We can conclude that the correct answer is the third one.
Answer:
i think the answer is option c
Answer:
(X=Y)=(3,6)
Step-by-step explanation:
5x-4(4x-6)=-9
x=3
y=4x3-6
y=6