1. L

    maclaurin series what am i doing wrong?

    hey guys ive attached a jpg with the question: f(x)= sin3x f'(x)= 3cos3x f''(x) = -3.3sin3x f'''(x) = 3.3.3cos3x I took a=0 and began to input it into the derivations: f(0) = 0 f'(0) = 3 f''(0) = 0 f''' (0) = 27 but when i put it into the maclaurin series i get 3x + 27x^3/3! shudnt i get the...
  2. B

    What am I doing wrong??

    I have questions about two problems and it be great if anybody could help me. First one is this one http://img123.imageshack.us/img123/8764/20459883.png +C is already included at the end, but it isn't taking it. Second one I don't know what to do with...
  3. K

    Where am I going wrong differentiating this?

    Differentiate with respect to t. y = 3sin^2(2t-4) -2cos^2(3t+1) y' = [[(6)(sin)(cos)](2t-4)](2) -[[(4)(cos)(-sin)](3t+1)](3) =12sincos(2t-4) +12cossin(3t+1) Answer is: y' = 12sin(2t-4)cos(2t-4) + 12cos(3t-1)sin(3t-1) Where did I go wrong? Also completely aside from this...
  4. T

    Arithmetic Sequence-What Am I Doing Wrong?

    Even if i try simplifying the fraction it doesn't come out to 65/2, which is the correct answer in the back of the book. Am i missing something? (Headbang)
  5. S

    Series => Convergent or Divergent? (I get 2/5 wrong)

    "Match each of the following with the correct statement. C stands for Convergent, D stands for Divergent. 1. 2. 3. 4. 5. " The above is what I did. But according to my school's computer system; 1 and 5 are wrong ... how/why? My logic for #1: The denominator gets super large...
  6. S

    I think I'm evaluating this series correctly but my school's system says it's wrong!

    Question: Given: Determine: (a) whether is convergent. (b) whether is convergent. My answer (and Wolfram Alpha's) is 1. I can even prove it with the Test for Divergence since the limit does not equal 0 and also the numerator is equal to denominator with some algebraic manipulation therefore...
  7. C

    Permutations and combinations(why do I always get them wrong?)

    Hello all! Probably one of the most difficult things for me in a high school math course is the application of permutations and combinations to real life problems. I just always, always, no matter how much I practice, get the wrong. The review book I am using introduces the following...
  8. N

    what i am doing wrong?

    what's wrong with this solution, because last integral doesn't integrate
  9. N

    whats wrong with my solution

    the last integral does not integrate : xy' - y=ln(y); x=(ln(y) + y)/y'; y' = p; x=(ln(y) + y)/p; dx=-1/p^2 (ln(y) + y)dp + (1/yp + 1/p)dy; (ln(y)/p^2 + y/p^2)dp=dy/yp; dp/p = dy/(yln(y)+y^2)
  10. S

    is it possible for a basis to have 1 vector or am I doing something wrong?

    question: let W be a subspace spanned by the vectors: {v_1=(2,0,-1,3) v_2=(1,2,2,-5) v_3=(3,2,1,-2) v_4=(7,2,-1,4)} Find the basis W^{\perp} work:let u=(a,b,c,d) be in W^{\perp} then u \cdot v_1=0, u \cdot v_2 = 0, u \cdot v_3 = 0, u \cdot v_4 = 0 So we've got the following matrix augmented...