ikhlas Posted March 29, 2005 Share Posted March 29, 2005 Please guys any help here and as usual with detailed answer , if you may 1 ) How many cubes, each having a surface area of 54 sq in , will fit exactly inside a larger cube having a surface area of 216 sq in ?? The answer is 8 ? The surface area cube is 6*(x 2 ) , but I think we didn't need to do this ?? And any q ask us how many cub means volume ? am right ? By the way what is the surface area for cylinder , I think the same = pi * r2 *h , but my q is the surface area for cylinder is the same as the area for cylinder ?? We have two cercal?? 2) If we have line which intercept in ( 5,0,) and in (0 , 3 ) , ( please imagine that ) , which is the following equations describes the line drawn for this line ? The answer is y = -1/2x + 2 , how we can know that ?? just pick any sopt or it must from the q ?? i hope you understand me guys ?? ikhlas Quote Link to comment Share on other sites More sharing options...
reactor Posted March 29, 2005 Share Posted March 29, 2005 1.a yes :D 1.b surface area = area o of a cylinder = pi * r2 *h volume of a cylinder = pi^2 * r * h 2 if you plug in y=0 then you should get x=5 and if you plug in y=3 you should get x=0. Yuo want the equation that has the above properties. :D Quote Link to comment Share on other sites More sharing options...
metodiev Posted March 29, 2005 Share Posted March 29, 2005 2) If we have line which intercept in ( 5,0,) and in (0 , 3 ) , ( please imagine that ) , which is the following equations describes the line drawn for this line ? The answer is y = -1/2x + 2 , how we can know that ?? just pick any sopt or it must from the q ?? i hope you understand me guys ?? ikhlas the general form of a line is y = ax + b a and b are coefficients and can be calculated although the substitution approach by gstergia works it may be slow if you have to substitute in a number of equations. The good news is that there is an alternative approach. the b in the formula above (oooops, looks like there is a mistake somewhere) represents the y-intercept when x=0 and in this problem b = 3 the a is the slope of the line which is rise/run = (y2 - y1)/(x2 - x1) and in this case is (0-3)/(5-0) = -3/5 so the equation must look like y = -3/5x + 3 check the answer I dont have time to go into more details but will elaborate if needed Quote Link to comment Share on other sites More sharing options...
ikhlas Posted March 29, 2005 Author Share Posted March 29, 2005 Hi metodive thanks for your helping . the b in the formula above (oooops, looks like there is a mistake somewhere) represents the y-intercept when x=0 and in this problem b = 3 the a is the slope of the line which is rise/run = (y2 - y1)/(x2 - x1) and in this case is (0-3)/(5-0) = -3/5 so the equation must look like y = -3/5x + 3 check the answer I dont have time to go into more details but will elaborate if neededi am sure , i get the same answer ,and i pluge how can i get this formula ?? ok if you want i will put the other choices . y = 2 x -1 y = x + 2 y = 1/2x + 2 y = 2 y = -1/2x +2 and my book say this is the answe ?!!but no details thanks Quote Link to comment Share on other sites More sharing options...
ikhlas Posted March 29, 2005 Author Share Posted March 29, 2005 thanks gstergia !! 1.a yes :D . please tell me how you get this answer ?? ( 8 how ??!! ) there is answer by S3 = S2 * S ,, ITHINK THIS IS NOT AS WE KENWO ?? 2 if you plug in y=0 then you should get x=5 and if you plug in y=3 you should get x=0. Yuo want the equation that has the above properties. :D thanks ikhlas Quote Link to comment Share on other sites More sharing options...
dagof Posted October 4, 2005 Share Posted October 4, 2005 1.a. (216/54)^1.5=8 1.b. surface=2*pi*r^2+2*pi*r*h 2. y=-3x/5+3 Quote Link to comment Share on other sites More sharing options...
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