Math problem: 25 out of 9 (- 4) * (- 169) That's it

Math problem: 25 out of 9 (- 4) * (- 169) That's it

Under the radical (- 4) * 25 of 9 * (- 169)
=2 * 3 / 5 * 13
=130 / 3
Do not understand can ask, help please adopt, thank you!

Compare size. (1) (radical 3) - 2___ Radical 2 - radical 3 (2) - 3 root sign 4___ -4 root sign 3

(1) (radical 3) - 2_ ＞__ Radical 2 - radical 3
(2) - 3 root sign 4_ ＞__ -4 root sign 3

1, radical 2, 1, Radix 2, 1, Radix 2 General term formula

An = 1.5 + 0.5 * (- 1 ^ n)

Root 2 (root 8 + 4 1 / 2 of root 12)

=√2×8+4√(2×1/2)-√2×12
=√16+4-√24
=4+4-2√6
=8-2√6

It is known that: 1 / root 2 + 1 = root 2-1, 1 / root 3 + root 2 = root 3-root 2, 1 / 2 + root 3 = 2-root 3 Please express the above equation with n (n is a positive integer)

It is 1 / √ [(n + 1) + √ n] = √ (n + 1) - √ n
In fact, because √ (n + 1) + √ n, and √ (n + 1) - √ n are reciprocal of each other, and their product is 1

Reduce root sign (- 1 / a)

If the root sign is meaningful, - 1 / a ≥ 0
So a < 0
Then | a | = - A
So the original formula = √ (- A / a 2)
=√(-a)/√a²
=√(-a)/|a|
=-√(-a)/a

Reduction of radical-a 3-A × radical-a / 1

√﹙﹣a³﹚－a√﹙﹣1/a﹚
＝﹣a√﹙﹣a﹚＋√﹙﹣a﹚
＝﹙1－a﹚√﹙﹣a﹚.

Reduce the root sign - a 3 - a radical - 1 / A

Yi Zhi a

If a ≤ 1, simplify: radical (1-A) 3 main process

A=0
Root number (1-A) 3
=|1-a|√(1-a)
=(1-a)√(1-a)

Simplification 1−sin2440°=______ .

1−sin2440°=|cos440°|=|cos（360°+80°）|=|cos80°|=|sin10°|=sin10°，
So the answer is: sin 10 °