In one sentence, describe what the following article is about: Hard water stains are both common and unsightly. Fortunately, you can remove them using items you may already have at home. One choice is lemon Kool-aid. Simply sprinkle 1 package of lemon Kool-aid around the toilet bowl, wait 1 hour, and use a toilet brush to scrub away stains. Lemon Kool-aid is available at most grocery stores for as little as $0.25. Pumice stones are excellent at scrubbing away hard water stains. Use a pumice stone you already have at home, or purchase a "pumie" (a pumice stone on a stick designed for this purpose). Soak your pumice stone in water for 10-15 minutes, then use it to scrub away stains. Dryer sheets are another great product for scouring away hard water stains. In fact, used dryer sheets seem to work even better than brand new ones! Wear a pair of rubber gloves, then use an ordinary dryer sheet (used or unused) to scrub away stains.
Summary: Apply lemon Kool-aid. Use a pumice stone. Scrub with a dryer sheet.

. Before you can start finishing your basement, you’ll need to make sure that you don’t have uncontrollable mold and moisture problems. Work to stop all mold in your basement and ensure that you can stop water from getting in. If you can’t, then you may need to consider that it would be unwise to continue. Once you know that it’s possible to finish your basement, you’ll need to create a budget to find out how much money you really have to work with. Don’t forget to take into account things like building supplies, extras, labor you’ll need to hire, and the items you’ll need to put in the basement like toilets and showers. Hiring a contractor or a designer may be a good idea, as they can help you figure out how much money you need and where you can save a few bucks. You’ll need drawn out plans, especially if you’re going to be doing the work yourself. You’ll need to know the lengths of all the walls you’ll put in, how much square footage of flooring material you’ll need, how much wall space you need to drywall, etc.  Draw out plans for your basement and the changes you plan on making and remember: measure twice, cut once! Before you continue, it is very important to get all of the necessary permits and inspections from your local building department. You wouldn’t want to go to all that work and then have someone tell you you need to take it down or worse: hit a surprise water main!
++++++++++
One-sentence summary -- Get your mold and moisture problems under control Budget for your renovations. Plan your renovations. Get any necessary permits and inspections.

Problem: Article: Whenever you wish to find the derivative of the square root of a variable or a function, you can apply a simple pattern. The derivative will always be the derivative of the radicand, divided by double the original square root. Symbolically, this can be shown as: If f(x)=u{\displaystyle f(x)={\sqrt {u}}}, then f′(x)=u′2u{\displaystyle f^{\prime }(x)={\frac {u^{\prime }}{2{\sqrt {u}}}}} The radicand is the term or function underneath the square root sign. To apply this shortcut, find the derivative of the radicand alone. Consider the following examples:  In the function 5x+2{\displaystyle {\sqrt {5x+2}}}, the radicand is (5x+2){\displaystyle (5x+2)}. Its derivative is 5{\displaystyle 5}. In the function 3x4{\displaystyle {\sqrt {3x^{4}}}}, the radicand is 3x4{\displaystyle 3x^{4}}. Its derivative is 12x3{\displaystyle 12x^{3}}. In the function sin(x){\displaystyle {\sqrt {sin(x)}}}, the radicand is sin⁡(x){\displaystyle \sin(x)}. Its derivative is cos⁡(x){\displaystyle \cos(x)}. The derivative of a radical function will involve a fraction. The numerator of this fraction is the derivative of the radicand. Thus, for the sample functions above, the first part of the derivative will be as follows:  If f(x)=5x+2{\displaystyle f(x)={\sqrt {5x+2}}}, then f′(x)=5denom{\displaystyle f^{\prime }(x)={\frac {5}{\text{denom}}}}  If f(x)=3x4{\displaystyle f(x)={\sqrt {3x^{4}}}}, then f′(x)=12x3denom{\displaystyle f^{\prime }(x)={\frac {12x^{3}}{\text{denom}}}}  If f(x)=sin⁡(x){\displaystyle f(x)={\sqrt {\sin(x)}}}, then f′(x)=cos⁡(x)denom{\displaystyle f^{\prime }(x)={\frac {\cos(x)}{\text{denom}}}} Using this shortcut, the denominator will be two times the original square root function. Thus, for the three sample functions above, the denominators of the derivatives will be:  For f(x)=5x+2{\displaystyle f(x)={\sqrt {5x+2}}}, then f′(x)=num25x+2{\displaystyle f^{\prime }(x)={\frac {\text{num}}{2{\sqrt {5x+2}}}}}  If f(x)=3x4{\displaystyle f(x)={\sqrt {3x^{4}}}}, then f′(x)=num23x4{\displaystyle f^{\prime }(x)={\frac {\text{num}}{2{\sqrt {3x^{4}}}}}}  If f(x)=sin⁡(x){\displaystyle f(x)={\sqrt {\sin(x)}}}, then f′(x)=num2sin⁡(x){\displaystyle f^{\prime }(x)={\frac {\text{num}}{2{\sqrt {\sin(x)}}}}} Put the two halves of the fraction together, and the result will be the derivative of the original function.  For f(x)=5x+2{\displaystyle f(x)={\sqrt {5x+2}}}, then f′(x)=525x+2{\displaystyle f^{\prime }(x)={\frac {5}{2{\sqrt {5x+2}}}}}  If f(x)=3x4{\displaystyle f(x)={\sqrt {3x^{4}}}}, then f′(x)=12x323x4{\displaystyle f^{\prime }(x)={\frac {12x^{3}}{2{\sqrt {3x^{4}}}}}}  If f(x)=sin⁡(x){\displaystyle f(x)={\sqrt {\sin(x)}}}, then f′(x)=cos⁡(x)2sin⁡(x){\displaystyle f^{\prime }(x)={\frac {\cos(x)}{2{\sqrt {\sin(x)}}}}}
Summary:
Learn the shortcut for derivatives of any radical function. Find the derivative of the radicand. Write the derivative of the radicand as the numerator of a fraction. Write the denominator as double the original square root. Combine numerator and denominator to find the derivative.