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Known vector M = (root 3sinx / 4,1), vector n = (cosx / 4, SiNx / 4) The original title is shown in the figure Ask an expert to answer
This is the problem: we know that vector M = (root sign 3sinx / 4,1), vector n = (cosx / 4, cos ^ 2, X / 4) 1. Multiply vector m by vector n = 1 to find the value of COS (π / 3 + x). 2. Remember f (x) = vector m times vector n. in triangle ABC, the opposite sides of angles a, B and C are a, B and C, and meet (2a-c) CoSb = bcosc, find the value of function f (a)
Given the vector a = (cosx, SiNx), B = (root 3, - 1), find the maximum value of | 2a-b |
a=(cos θ, sin θ), So | a | = root sign (COS) ²θ+ sin ²θ)= 1B = (√ 3,1), so | B | = root sign ((√ 3) ²+ (-1) ²)= 2a*b=cos θ* (√3)+sin θ* (-1)=(√3)cos θ- sin θ= 2cos( θ+ π/6)|2a-b| ²= (2a-b) ²= 4a ²- 4a*b+...
Find the coordinates of vector C whose included angles are equal to vectors a = (root 3, - 1), B = (1, root 3) and whose modulus is root 2
c=（a,b)
a^2+b^2=2;（1）
The included angle of vectors a and B is cosa = (a * b) / | a | B | = 0; that is, 90 degrees, and the included angle between C and them is 45 degrees
COSC = (a * c) / | a | C | = (root 3a-b) / 2 root 2 = root 2 / 2
Root 3a-b = 2; (2)
1,2 combination; b = 1, a = 1
How to represent segment root 5 and segment root 3 on the number axis? How do you draw vertically and horizontally? Pythagorean theorem I understand, but how to draw it How to determine the right angle edge when radical 5 is the bevel edge and how to determine the right angle edge and bevel edge when radical 3 is the right angle edge
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How to use Pythagorean theorem to draw the line segment of radical 5 on the number axis
Cross the origin of the number axis and make the vertical line of the number axis; Record as Y-axis;
Draw a circle with the origin as the center and 2 as the radius, and intersect the Y axis with a (0,2);
Draw a circle with point a as the center and 3 as the radius and intersect the x-axis with point B, then the distance from the origin to point B is √ 5
Make a point representing the root sign 5 on the number axis, with a graph, using the Pythagorean theorem,
Take the origin o as the starting point on the number axis, take 2 units of length to the right to obtain a (2,0), cross point a as a vertical line, and take 1 unit of length from a upward,
B (2,1)
Connect OB and get from Pythagorean theorem: OB ^ 2 = OA ^ 2 + AB ^ 2. = 2 ^ 2 + 1 ^ 2 = 5
So ob = √ 5
Use a compass to draw an arc with o as the center and ob as the radius, and intersect the number axis at C (√ 5,0). --- this point is the result
Sorry, I can't transmit the picture. Please draw it on the paper yourself
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