Actually Welcome to the Concept of the areas.
Since we know that, radius = diameter /2
here, => d = 2r ,
hence we use the formula as,
A = πr^2 ,
here option d.) is correct.
This is basically asking if each transformation is an isometry, which maps a triangle to a congruent triangle.
(x,y)⇒(-y,x) That's an isometry, not scaling x or y. I think it's a 90 degree rotation. CONGRUENT
(x,y)⇒(x-2,y-1/2) No scaling, pure translation. CONGRUENT
(x,y)⇒(2x,2y) That's a double scaling so NOT CONGRUENT
(x,y)⇒(-x,y) That's a reflection. CONGRUENT
(x,y)⇒(1/2 x, 1/2 y) Scaling again, NOT CONGRUENT
We have the following expression:
(6.34 x 10 ^ -7) (4.5 x 10 ^ 3)
The solution shown is:
(6.34 x 10 ^ -7) (4.5 x 10 ^ 3)
(6.34 x 4.5) (10 ^ -7 x 10 ^ 3)
28.53 x 10 ^ -4
-28.53 x 10 ^ 4
-2.853 x 10 ^ 3
The errors are:
A. He changed the sign of the coefficient. A negative exponent does not affect the sign of a coefficient in scientific notation. The sign of the exponent determines the direction the decimal is moved in.
D. He got the wrong value for the coefficients; 28.53 x 10^-4 is not possible. The coefficients in scientific notation are always greater than 1, but less than 10.
