The pH of a substance equals - log H where H is the concentration of hydrogen ions. Suppose the hydrogen ion concentration is 4 times greater for Substance A then Substance B. What is the difference between the pH levels?
O 0.4
O log4
04
O log10

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b