10 * 10^2 - 7.79* 10^3
they have to be to the same power to add or subtract
change 10*10^2 to proper scientific notation (only 1 number before the decimal) 1*10^3
1*10^3 - 7.79*10^3 = (1-7.79) * 10^3=-6.79*10^3
Cos = adjacent / hypotenuse
cos 25° = 4 / AB
cos 25° • AB = 4 / AB • AB
AB cos 25° ÷ cos 25° = 4 ÷ cos 25°
AB = 4/cos 25°
AB = 4.41 (nearest hundredth)
Answer:
only 3) is true. EC is equidistant (the same distance) to BD
Step-by-step explanation:
since we have no coordinates or other specific distance information for the various points and lines, we can only confirm statements that must be true for any placement of the lines inside a circle with the described attributes.
the distance EC could be the same as CB, but if we move ED further up or down in the circle (still parallel to CB), we can easily see, that this is not a general case.
the same for CB and BD.
since CB and BD are airways parallel to each other, the symmetry principle of a circle requires that the distance of EC is airways equal to the distance of BD for all such possible pairs of parallel lines inside the circle.
the graph itself gives an example that the distance CB and the distance ED do not have to be the same. they can be for certain pairs of parallel lines in the circle, but not for all of them.
B)
Because if you find the degrees for angle 1 you get:
180⁰ - 45⁰- 39⁰ = 96⁰ <- angle 1
The triangle in the center has 3 angles, and those 3 angles will equal 180⁰
So, 180⁰ - 96⁰ = 84⁰
Refer to the other answer to see how letter c was done
<h2>
Answer:</h2>
cos 28°cos 62°– sin 28°sin 62° = 0
<h2>
Step-by-step explanation:</h2>
From one of the trigonometric identities stated as follows;
<em>cos(A+B) = cosAcosB - sinAsinB -----------------(i)</em>
We can apply such identity to solve the given expression.
<em>Given:</em>
cos 28°cos 62°– sin 28°sin 62°
<em>Comparing the given expression with the right hand side of equation (i), we see that;</em>
A = 28°
B = 62°
<em>∴ Substitute these values into equation (i) to have;</em>
<em>⇒ cos(28°+62°) = cos28°cos62° - sin28°sin62°</em>
<em />
<em>Solve the left hand side.</em>
<em>⇒ cos(90°) = cos28°cos62° - sin28°sin62°</em>
⇒ 0 = <em>cos28°cos62° - sin28°sin62° (since cos 90° = 0)</em>
<em />
<em>Therefore, </em>
<em>cos28°cos62° - sin28°sin62° = 0</em>
<em />
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