What is sin70 ° (sin25 + cos25 °) equal to

What is sin70 ° (sin25 + cos25 °) equal to

The solution sin 70 ° (sin 25 + cos 25 °)
=sin70°√2(√2/2sin25+√2/2cos25°)
=sin70°√2(cos45°sin25+sin45°cos25°)
=sin70°√2sin（45°+25°）
=√2sin70°sin70°
=√2sin²70°
sin70°(sin25°+cos25°)
= √2 * (√2/2 * sin25° + √2/2 * cos25°) * sin70°
= √2 * (sin25° * cos45° + cos25° * sin45°) * sin70°
= √2 * sin(25° + 45°) * sin70°
= √2 * sin70° * sin70°
= √2 * (sin70°)^2
sin70°×(sin25+cos25°) = 0.72728077672417
sin70°(sin25+cos25°)
=sin(45+25)°*(sin25+cos25°)
=(sin45cos25+sin25cos45)*(sin25+cos25)
=Radical 2 / 2 (sin25 + cos25) * (sin25 + cos25)
=Radical 2 / 2 [sin ^ 2 (25) + cos ^ 2 (25) + 2sin25cos25]
=Radical 2 / 2 [1 + sin50]
Square of x = 4x to solve the equation
x²=4x
At the same time △ x
X=4
What is the sum of sin70 in that math
zero point nine three nine six nine two six two
It is known that the solution of the linear equation 5x-2a = - 4-x with respect to X is greater than 2 and less than 10, then the value range of a is
5x-2a=-4-x
5x-2a+4+x=0
6x-2a=-4
x=(2a-4)/6
∵ the solution is greater than 2 and less than 10
∴2＜(2a-4)/6＜10
That is 12 ＜ 2a-4 ＜ 60
The range of a is 8 < a < 32
5x-2a = - 4-x solves x = (2a-4) / 6 and 2
How much is sin70?
You'd better give out your whole topic
If it's just 70 degrees=——
Then I can tell you responsibly
Just ask the calculator
No calculator?
Then you may not do it
Basically can't calculate... Calculator can
Sin70 = 0.93969
In mathematics, it is calculated by Taylor expansion
sinx=x-x^3/3!+x^5/5!-......
Tell you the way of thinking, sin70 = sin (60 + 10)
The value of sin10 can be derived from two formulas sin30 = sin (20 + 10), sin20 = 2sin10cos10. In fact, the triple angle formula also has sin (3x) = 3six (x) - 4sin & sup3; (x)
This kind of problem is important in thinking, there is no need to consider the operation
1. Look up table 0.9397
2. Use calculator 0.939692620785908
3. Substituting α = 70 degrees into the triple angle formula sin (3 α) = 3sin α - 4sin ^ 3 α
Let x = 70 degrees, and we get 3x-4x ^ 3 = sin210 degrees = - 1 / 2
It is found that 8x ^ 3-6x-1 = 0, and then it is solved by the root formula of univariate cubic equation.
If the solution of the linear equation 4x-2m = 5x-9 with respect to X is negative, then the value range of M is?
4x-2m=5x-9
-x=2m-9
x=9-2m
The solution is negative
9-2m9/2
4x-2m=5x-9
x=9-2m
The solution is negative
Then: 9-2m9
m>9/2
Then x = - 2m + 9 is always negative
-2m+99/2
Why sin40 / 2sin20 = cos20
Sin40 = sin (2x20) = 2sin20cos20, which is a double angle formula
therefore
Sin40 degree / 2sin20 degree = cos20 degree
Why is sin70 equal to cos20
70 degrees + 20 degrees = 90 degrees (60 = cos30)
The two corners are complementary to each other. It has to be proved that the teacher only mentioned it, but did not say it in detail
Square of (2x + y) + (4x + 2Y) (2x-y) + (2x-y)
It's a calculation problem
(2X+Y)^2+（4X+2Y)(2X-Y)+（2X-Y）^2
=(2X+Y)^2+2(2X+Y)(2X-Y)+(2X-Y)^2
=[(2X+Y)+(2X-Y)]^2
=(4X)^2
=16X^2
=Square of (2x + y) + 2 (2x + y) (2x-y) + (2x-y)
=The square of (2x + y + 2x-y)
=Square of 4x
=Square of 16 * x
What is the value of 2sin20 + cos10 + tan20sin10
2sin20 + cos10 + tan20sin10 = 2sin20 + cos10 + sin20sin10 / cos20 = 2sin20 + (cos10cos20 + sin10sin20) / cos20 = 2sin20 + cos10 / cos20 = 2sin20 + cos10 / cos20 = (sin40 + cos10) / cos20 = (cos50 + cos10) / cos20 reuse and differential product